CHAPTER 31
Anorectal Dysfunction
KEY POINTS
18041 Defecatory dysfunction and fecal incontinence are common conditions that have
tremendous psychosocial and economic implications.
2 The differential diagnosis for anorectal dysfunction is broad and can be classified into
systemic factors, anatomic/structural abnormalities, and functional disorders.
3 A thorough history, physical examination and appropriate ancillary testing are critical
for the evaluation of fecal incontinence and defecatory dysfunction.
4 Treatment of anorectal dysfunction should focus on nonsurgical management before
surgery, which should be reserved for those with poor response to noninvasive
treatment.
5 Sacral nerve stimulation should be considered the procedure of choice for moderate
to severe fecal incontinence that does not respond to conservative measures and
biofeedback.
6 Overlapping sphincteroplasty is an alternative for patients with a disrupted anal
sphincter in whom conservative therapies have failed.
Anorectal dysfunction encompasses a variety of conditions that disrupt
normal anorectal function. Such conditions can be subdivided into those that
cause constipation (defecatory dysfunction) and those that result in fecal
incontinence. The evaluation and treatment of anorectal dysfunction involves the
expertise of several medical and surgical specialties, mainly urogynecologyfemale pelvic medicine, gastroenterology, and colorectal surgery. The
pathophysiology, evaluation, and management of conditions relevant to
gynecologists are presented in this chapter.
NORMAL COLORECTAL FUNCTION
Anal continence and defecation are complex physiologic processes that
require intact and coordinated neurologic and anatomic function. Necessary
elements include colonic absorption and motility, rectal compliance,
anorectal sensation, and the multifaceted continence mechanism. An
understanding of normal physiology and pathophysiology is essential to the
treatment of women with anorectal dysfunction.
Stool Formation and Colonic Transit
The colon plays an important role in absorption and regulation of water and
electrolytes. As much as 5 L of water and associated electrolytes can be
absorbed in a single day. The parasympathetic-mediated peristaltic contraction
of colonic smooth muscle normally transfers fecal material to the rectum. There is
a delay in stool transit at the rectosigmoid region that allows for maximal
absorption of water and sodium.
1805Storage
As stool accumulates in the rectosigmoid, the rectal distention triggers the
rectoanal inhibitory reflex, a transient decrease in the internal anal sphincter
(IAS) tone and an increase in the external anal sphincter (EAS) tone.
Exposure of the anal canal to fecal matter facilitates sampling, whereby the
anal canal and its abundant sensory nerves determine stool consistency (i.e.,
solid, liquid, or gas). Accommodation occurs as the normally compliant rectal
vault relaxes in response to increased volume. This cycle, combined with
increased rectal distention, stimulates an urge to defecate. This urge can be
voluntarily suppressed through cortical control, resulting in further
accommodation and activation of the continence mechanism.
Continence Mechanism
Muscles
The key muscles of the continence mechanism are the puborectalis, IAS, and
EAS. The paired puborectalis muscles originate from the pubic rami at the level
of the arcus tendineus levator ani and pass laterally to the vagina and rectum in a
U-shaped configuration, creating a sling around the genital hiatus. Contraction of
the puborectalis muscles narrows the genital hiatus, and pulls the rectum
anteriorly, producing the near 90-degree anorectal angle. The resting tone of the
puborectalis muscle serves as the primary continence mechanism for solid
stool. The IAS and EAS are essential for continence of flatus and liquid stool.
The IAS maintains most of the resting tone for the sphincter complex through
autonomic reflex arcs and is essential for passive continence. Although the EAS
maintains constant resting tone, it is ultimately responsible for preventing fecal
urgency and stress incontinence of stool associated with sudden increases in intraabdominal pressure. This function is under voluntary and involuntary control. The
final anatomic barrier of the continence mechanism is the seal provided by
coaptation of the anal cushions occluded by pressure within the hemerrhoidal
veins.
Nerves
Denervation is a common pathway for pathologic states to disrupt normal
function. The IAS receives its sympathetic innervation from L5, which passes
through the pelvic plexus via the hypogastric plexus. The parasympathetic
supply from S2–S4 synapses at the pelvic plexus, where it joins the sympathetic
nerves. In addition to the parasympathetic and sympathetic components, the
autonomic nervous system of the gut has an enteric nervous system (ENS). The
1806ENS provides local circuitry that can contract or relax the gut muscles, and
impact absorption and secretion. The autonomic ganglia of the ENS, located in
the gut, are interconnected to provide local integration and processing of
information. The IAS acts through reflex arcs at the spinal cord without voluntary
control. The puborectalis (levator ani) is innervated bilaterally by branches of the
S2–S4 sacral roots and does not receive direct innervation from the pudendal
nerve (1,2). The EAS is innervated bilaterally by the pudendal nerve (S2–S4) via
Alcock canal. The pudendal nerve fibers cross over at the level of the spinal cord,
allowing preservation of EAS function in the event of unilateral damage. The rich
sensory supply from the anal canal travels along the inferior rectal branch of the
pudendal nerve.
Evacuation
Initiation of defecation is normally under cortical control. Delivery of stool to
the rectum stimulates the rectoanal inhibitory reflex, permitting sampling
followed by accommodation. Further rectal distention results in an urge to
defecate. Evacuation occurs with voluntary relaxation of the pelvic floor muscles
(puborectalis muscle and EAS) in conjunction with increased intra-abdominal and
intrarectal pressure from Valsalva. This results in widening of the anorectal angle
and shortening of the anal canal, which facilitates emptying. Coordinated
peristaltic activity of the rectosigmoid assists evacuation. After this process is
complete, the closing reflex is initiated, resulting in contraction of the pelvic floor
muscles and reactivation of the continence mechanism.
EPIDEMIOLOGY
The epidemiology of anorectal dysfunction has been best defined in terms of the
incidence and prevalence of fecal incontinence. Few studies have been done to
assess the incidence and prevalence of defecatory dysfunction.
Defecatory Dysfunction
The term defecatory dysfunction often is used synonymously with the symptom of
constipation. Constipation is an imprecise term used by patients to report a
variety of symptoms, including infrequent stools, dyschezia, straining,
variation in stool consistency and caliber, incomplete emptying, bloating, and
abdominal pain. The most common symptoms associated with constipation
are straining and hard stools (3). Defecatory dysfunction is defined by many
physicians as infrequent stools, typically fewer than three bowel movements
per week. This definition is based on stool frequency studies in which 95% of
1807women have more than three bowel movements per week. Using this definition,
the prevalence of constipation should be 5% (4). However, the prevalence of
constipation has been estimated to range from 2% to 28%, depending on the
definition applied (5,6).
The prevalence of constipation is higher among women, elderly
individuals, nonwhite individuals, and those with low income, and low
education levels (3,7). Based on an estimated 2.5 million visits to U.S. physicians
per year for constipation (8), the annual cost for evaluation of constipation would
be over $7 billion. Direct individual annual costs of chronic constipation range
from $1,912 to $7,522 per year (9). An estimated 85% of physician visits result in
a prescription; thus, inclusion of drug costs would increase this amount
substantially (8). Aside from economic burden, constipation has a detrimental
effect on health-related quality of life (QoL), which contributes to the indirect
costs of this disease (3,9,10).
Fecal Incontinence
The reported prevalence of fecal incontinence varies between 2% and 3% for
community-dwelling individuals, 3% to 17% for those of increased age, and
46% to 54% for nursing home residents (11,12). A prevalence of 28% has been
reported among patients seeking benign gynecologic care and 36% of primary
care patients surveyed (13). The prevalence of fecal incontinence in the United
States is expected to increase 59% from 10.6 million in 2010 to 16.8 million in
2050 as the population ages (14). Epidemiologic studies of fecal incontinence are
compromised by social stigmata and the lack of a uniform definition. Definitions
of fecal incontinence vary with respect to the type of material passed (solid,
liquid, or gas), the frequency and duration of events (once in a lifetime to
twice a week), and the impact on QoL. Most authors agree that the true
prevalence of this condition is underestimated in the scientific literature (15). A
large health survey in the United States found age, female sex, physical
limitations, and poor general health to be independent risk factors associated with
fecal incontinence (16).
[1] Fecal incontinence has tremendous psychosocial and economic implications
for individuals and society as a whole. The loss of such a basic function can be
emotionally devastating, leading to poor self-esteem, depression, social isolation,
and decreased QoL (12,13,17). Fecal incontinence is the second leading reason
for nursing home placement in the United States, even though less than one-third
of individuals with this condition seek medical attention (12,17). The overall
annual cost to treat fecal incontinence is difficult to pinpoint (17).
1808SYMPTOM-BASED APPROACH TO COLORECTAL DISORDERS
Several medical conditions cause defecatory dysfunction, fecal incontinence, or
combined symptoms. [2] The differential diagnosis is organized into a
classification system based on systemic factors, anatomic/structural abnormalities,
and functional disorders.
Differential Diagnosis
Disordered Defecation
Causes of defecatory dysfunction have traditionally been divided into systemic
disorders and idiopathic constipation (all nonsystemic causes). Idiopathic
constipation can be subdivided into anatomic/structural abnormalities and
functional disorders (Table 31-1).
Diabetes, hypothyroidism, and pregnancy are the most common
endocrinologic systemic factors that cause constipation, and all have a
component of decreased gastrointestinal motility and intestinal transit. In one
study, gastrointestinal symptoms were present in 76% of patients with diabetes,
including constipation, which occurred in 60% (18). In patients with diabetes,
constipation is believed to be secondary to intestinal autonomic neuropathy,
resulting in delayed or absent gastrocolic reflex and decreased bowel motility.
This enteric neuropathy may also cause gastroparesis and diarrhea. Although
diabetes has been classified with the endocrinologic causes, it should be grouped
with the enteric neuropathies. Pregnancy is not considered a disease state;
however, there is an 11% to 38% prevalence of constipation that is believed to
result primarily from the effect of progesterone on smooth muscle (19–21). Other
contributors to constipation during pregnancy include medication use (e.g., iron,
ondansetron) and poor oral fluid intake (e.g., dehydration, nausea/vomiting of
pregnancy) (21). Postpartum constipation is even more common, likely worsened
by pain and discomfort from hemorrhoids and perineal repair (22).
The systemic neurologic factors can be divided into central and peripheral
processes. Spinal cord lesions, multiple sclerosis, and Parkinson disease affect
the autonomic nervous system. Trauma to the sacral nerves often leads to severe
constipation from decreased left-sided colonic motility, decreased rectal tone and
sensation, and increased distention. These findings are seen in patients with
myelomeningocele, damage to the lumbosacral spine, and pelvic floor trauma
(23,24). Higher spinal cord lesions result in delayed sigmoid transit and decreased
rectal compliance. In these upper motor neuron lesions, colonic reflexes are
intact, and defecation can be initiated by digital stimulation of the anal canal (25).
Individuals with multiple sclerosis can have no gastrocolic reflex, decreased
1809colonic motility, decreased rectal compliance, and even rectosphincteric
dyssynergia (26). Constipation worsens with the duration of illness and may be
compounded by the side effects of medical therapy. Similar findings of
rectosphincteric dyssynergia and medication side effects are present with
Parkinson disease.
Among the peripheral neurogenic disorders, dysfunction occurs at the level of
the ENS. The ultimate example of this is congenital aganglionosis (Hirschsprung
disease). The absence of intramural ganglion cells in the submucosal and
myenteric plexuses of the rectum causes loss of the rectoanal inhibitory reflex.
Patients with this illness usually present with functional obstruction and proximal
colonic dilation. In most patients, the condition is diagnosed within 6 months of
age, although milder cases can be seen later in life.
Other systemic factors to consider are collagen vascular and muscle disorders.
Some of the most commonly used prescription and over-the-counter medications,
including aluminum antacids, beta blockers, calcium channel blockers,
anticholinergics, antidepressants, and opiates, cause defecatory dysfunction
(Table 31-2). Lifestyle issues, such as inadequate fiber intake and insufficient
fluid intake, can exert similar effects independently or in conjunction with other
disorders.
Structural abnormalities refer to the obstructive disorders, such as pelvic
organ prolapse, perineal descent, intussusception, rectal prolapse, and
tumors. Functional disorders are those that do not have an identifiable
anatomic or systemic etiology. Most functional disorders are motility
disorders, such as slow-transit constipation/colonic inertia, irritable bowel
syndrome (IBS) (constipation predominant), and functional constipation
(FC). The Rome IV Criteria created strict definitions for these idiopathic
conditions (Table 31-3) that are believed to result from the complex interaction of
psychosocial factors and altered gut physiology via the gut–brain axis (27). This
classification started as a somewhat arbitrary system, as several of these
conditions are interrelated, however evidence-based adjustments have been made
(28).
Table 31-1 Causes of Defecatory Dysfunction and Fecal Incontinence
Fecal
Incontinence
Defecatory
Dysfunction
Systemic Factors
Metabolic/Endocrine
1810• Diabetes mellitus •
• Thyroid disease •
Hypercalcemia •
Hypokalemia •
Neurologic
• Central Nervous System •
Multiple sclerosis, Parkinson disease, stroke,
tumor, dementia
• Peripheral Nervous System •
Hirschsprung disease, spina bifida, autonomic
neuropathy, pudendal neuropathy
Infectious
• Bacterial, viral, parasitic diarrhea
Collagen Vascular/Muscle Disorder
Systemic sclerosis, amyloidosis, myotonic
dystrophy, dermatomyositis
•
Idiopathic/Autoimmune
• Inflammatory bowel disease
• Food allergy
Medications
• Prescription, over the counter •
Anatomical/Structural Abnormalities
Pelvic Outlet Obstruction
• Pelvic organ prolapse •
• Descending perineum syndrome •
Anismus/rectosphincteric dyssynergia •
1811• Intussusception, rectal prolapse •
Volvulus •
• Neoplasia •
• Benign strictures •
• Hemorrhoids •
Anal Sphincter Disruption/Fistula
• Obstetrical trauma
• Surgical trauma
• Anal intercourse
• Injury (trauma, radiation proctitis)
Functional
Motility Disorders
Global motility disorder •
Colonic inertia/slow-transit constipation •
• Irritable bowel syndrome •
Functional constipation •
• Functional diarrhea
Functional Limitations
• Decreased mobility •
• Decreased cognition •
Table 31-2 Drugs Associated with Constipation
Over-the-Counter Medications
Antidiarrheals (loperamide,
Kaopectate)
1812Antacids (with aluminum or
calcium)
Iron supplements
Prescription Medications
Anticholinergics Others
Antidepressants Iron
Antipsychotics Barium sulfate
Antispasmodics Metallic intoxication (arsenic, lead,
mercury)
Antiparkinsonian drugs Opiates
Antihypertensives Nonsteroidal anti-inflammatory agents
Calcium channel blockers Anticonvulsants
Beta blockers Vinca alkaloids
Diuretics 5-HT3 antagonists (ondansetron,
granisetron)
Ganglionic blockers
Fecal Incontinence
Fecal incontinence is defined as the involuntary loss of solid or liquid stool.
Anal incontinence is defined as the involuntary loss of solid or liquid stool or
flatus. Anal continence depends on a complex interaction of cognitive,
anatomic, neurologic, and physiologic mechanisms. The continence
mechanism can often compensate for a deficiency in one of these processes, but it
can be overwhelmed over time with increased severity or decreased function.
Systemic etiologies of fecal incontinence often are the result of disease states that
cause diarrhea. The rapid transport of large volumes of liquid stool to the rectum
can produce urgency and incontinence even in individuals with healthy
continence mechanisms (29). Fecal incontinence frequently results from
infectious diarrhea caused by bacteria (e.g., Clostridium, Escherichia coli,
Salmonella, Shigella, Yersinia, Campylobacter), viruses (e.g., Rotavirus,
Norwalk, human immunodeficiency virus [HIV]), and parasites (e.g., Entamoeba,
Giardia, Cryptosporidium, Ascaris). Numerous medications and dietary items
1813cause diarrhea and fecal incontinence (Table 31-4). Endocrine factors that can
lead to fecal incontinence include diabetes mellitus and hyperthyroidism. With
diabetes, diarrhea can develop from autonomic dysfunction, bacterial overgrowth,
osmotic diarrhea with sugar substitutes, and pancreatic insufficiency.
Inflammatory bowel disease is considered an idiopathic/autoimmune systemic
factor. Ulcerative colitis and Crohn disease cause fecal incontinence during
exacerbations with bouts of bloody diarrhea. Inflammatory bowel disease can
result in structural abnormalities, such as anal fissures, fistulas, abscesses, and
operative complications that lead to fecal or anal incontinence.
Table 31-3 Rome IV Criteria (27)
C. Bowel Disorders
C1. Irritable bowel syndrome (IBS)
IBS with predominant constipation
(IBS-C)
IBS with predominant diarrhea (IBSD)
IBS with mixed bowel habits (IBS-M)
IBS unclassified (IBS-U)
C2. Functional constipation
C3. Functional diarrhea
C4. Functional abdominal
bloating/distension
C5. Unspecified functional bowel
disorder
C6. Opioid-induced constipation
F. Anorectal Disorders
F1. Fecal incontinence
F2. Functional anorectal pain
F2a. Levator ani syndrome
F2b. Unspecified functional
anorectal pain
F2c. Proctalgia fugax
F3. Functional defecation disorders
F3a. Inadequate defecatory
propulsion
F3b. Dyssynergic defecation
Table 31-4 Drugs and Dietary Items Associated with Diarrhea
Over-the-Counter Medications
Laxatives
Antacids (with magnesium)
Prescription Medications
Laxatives Chemotherapy
Diuretics Colchicine
1814Thyroid preparations Cholestyramine
Cholinergics Neomycin
Prostaglandins Para-aminosalicylic acid
Dietary Items
Dietetic foods, candy or chewing gum, and elixirs with sorbitol, mannitol, or xylitol
Olestra
Caffeine
Ethanol
Monosodium glutamate
As with defecatory dysfunction, neurologic causes of fecal incontinence can
be divided into central and peripheral disorders. Among the central nervous
system disorders, upper motor neuron lesions above the level of the
defecation center (located in the sacral cord) cause spastic bowel dysfunction.
Cortical communication is disrupted, resulting in impaired cognitive control and
sensory deficit. The anal sphincter is under spastic contraction, but digital
stimulation can be performed to initiate reflex evacuation. Head trauma,
neoplasms, and cerebral vascular accidents that damage portions of the
frontal lobe result in loss of control of both micturition and defecation.
Greater loss of inhibition is present when the lesion is located more anteriorly in
the frontal lobe. Spinal cord trauma and lower motor neuron lesions above the
defecation center tend to cause permanent loss of cortical control. For 2 to 4
weeks following spinal cord injury, “spinal shock” occurs, resulting in a
temporary loss of reflexes below the level of the lesion, flaccid bowel function,
constipation, and fecal impaction. After the initial shock, spastic paralysis ensues
with hyperactive bowel function. The gastrocolic reflex, along with digital
stimulation, initiates reflex evacuation in the absence of cortical inhibition.
Fortunately, IAS tone is maintained despite the loss of EAS control for stress and
urge situations. Both constipation and fecal incontinence can occur in these
patients.
The demyelination that is seen in multiple sclerosis is randomly distributed and
can occur at any level in the central nervous system. In addition to the somatic
disruption that is similar to spinal cord injury, autonomic dysfunction frequently
is present. People with dementia and other degenerative disorders that cause
cognitive impairment frequently have fecal incontinence caused by overflow
1815incontinence as a result of constipation. Although sensory nerves are
functioning properly, these individuals lack the cognitive awareness necessary to
inhibit defecation until a socially acceptable time, and they develop overflow
incontinence.
Lower motor neuron lesions occurring at or below the level of the
defecation center in the sacral cord cause flaccid bowel dysfunction. Cortical
communication is disrupted, resulting in impaired cognitive control and sensory
deficit. The bowel reflexes, including the bulbocavernosus and anal reflexes, are
interrupted. The anal sphincter is flaccid, and fecal retention with overflow
incontinence usually occurs. Digital disimpaction and Valsalva often are required
for evacuation. Digital stimulation has no effect, and medications tend to work
poorly. Examples of motor neuron lesions include tumor or trauma to the cauda
equina, tabes dorsalis, spina bifida, and peripheral neuropathy.
The classic example of peripheral neuropathy is congenital aganglionosis
(Hirschsprung disease). The most common peripheral neuropathy occurs with
diabetes. Diabetic enteropathy occurs in up to 75% of patients and may
manifest as a variety of gastrointestinal symptoms. Approximately 20% of
individuals with diabetes have fecal incontinence (30,31). The cause tends to
be multifactorial with the exact mechanism uncertain. The long-standing belief
that vagal autonomic neuropathy is the primary cause of diabetic enteropathy has
been challenged by newer theories of hyperglycemia causing oxidative stress on
neural networks affecting the small bowel (31). Fecal incontinence can occur with
diabetic diarrhea or years later from progressive disease. Individuals with diabetes
frequently experience intestinal autonomic neuropathy, an abnormal gastrocolic
reflex, and chronic constipation. The subsequent pelvic floor denervation causes
fecal incontinence by sensory neuropathy, failure of the rectoanal inhibitory
reflex, and sphincter dysfunction (32). Consequently, fecal incontinence from
peripheral neuropathy can be the result of defective sampling, a disrupted
rectoanal inhibitory reflex, small intestine neuronal oxidative stress, or pudendal
neuropathy with sphincter dysfunction.
Anatomic and structural causes of fecal incontinence are usually caused by
obstetric or surgical trauma. Damage or dysfunction of the IAS, EAS, and
puborectalis can result in varying degrees of anal incontinence. Those with
impaired resting tone from a defective IAS will have passive incontinence
(incontinence at rest), which is worse during sleep when there is decreased EAS
activity (33). An inability to respond to sudden distention and to suppress
defecation is often seen with EAS dysfunction. EAS and IAS dysfunction often
results in incontinence of liquid stool. Incontinence of solid stool is usually seen
with widening of the anorectal angle from damage to the puborectalis muscles.
Damage to the anal cushions usually causes minor soiling. Other anatomic and
1816structural abnormalities associated with fecal incontinence include obstructive
disorders such as pelvic organ prolapse, descending perineum syndrome, anismus,
and intussusception; fistulas from diverticulitis, inflammatory bowel disease,
cancer, or surgical trauma; and decreased rectal compliance from inflammatory
bowel disease, cancer, and radiation. Decreased compliance results in higher
intraluminal pressures with smaller volumes of stool, poor storage capacity,
urgency, and incontinence (34).
Functional disorders associated with fecal incontinence include IBS
diarrhea variant (IBS-D), functional diarrhea, decreased mobility, and
decreased cognition.
Combined Disorders of Defecation and Fecal Incontinence
Several conditions have the potential to cause both defecatory dysfunction
(constipation) and fecal incontinence (see Table 31-1). Most of these disorders
cause combined symptoms through the development of fecal impaction followed
by overflow incontinence. This situation can be seen with many of the neurologic
conditions, pelvic outlet obstructive disorders, functional disorders of IBS,
decreased mobility, and decreased cognition. The cause of these symptoms often
is multifactorial.
Structural Versus Functional Disorders
Disordered Defecation
Disordered defecation (constipation) can result from outlet obstruction or
functional motility disorders.
Outlet Obstruction
Anismus/Rectosphincteric Dyssynergia
Anismus is also known as rectosphincteric dyssynergia, pelvic floor dyssynergia,
dyssynergic defecation, spastic floor syndrome, and paradoxical puborectalis
syndrome. The anorectal angle narrows as a result of paradoxical contraction of
the puborectalis and EAS during defecation, instead of relaxation. Frequent
symptoms include dyschezia, straining, hard stools, incomplete emptying, and
tenesmus. A prospective study of 120 consecutive patients with dyssynergic
defecation found a higher prevalence in women (77%) (35,36). The need for
digital assistance (digital disimpaction or splinting) to evacuate the rectum occurs
in up to 58% of patients. Psychosocial factors, such as a history of sexual
abuse, depression, eating disorder, obsessive-compulsive disorder, and stress,
may play an important role in this disease. In this study, 22% reported a history
1817of sexual abuse, and 31% reported a history of physical abuse. One-third believed
the problem began during childhood, and 24% reported a precipitating illness or
surgery was related to a particular event. Five percent of women claimed that
pregnancy or childbirth was a precipitating factor. This condition is seen in young
children with constipation and dyschezia. The response to biofeedback and pelvic
floor physical therapy, and the aforementioned patient characteristics, indicate a
learned response mechanism is involved (35,36). While this is categorized as an
outlet obstruction, the Rome IV Criteria for functional gastrointestinal disorders
places this in the category of functional defecation disorders (Table 31-3). The
specific Rome IV Diagnostic Criteria for dyssynergic defecation includes
“inappropriate contraction of the pelvic floor as measured with anal surface EMG
or manometry with adequate propulsive forces during attempted defecation” (37).
Pelvic Organ Prolapse
Pelvic organ prolapse bears special mention because it is often seen by
gynecologists but inconsistently associated with defecatory dysfunction.
Prolapse is very common, although many women with this condition are
asymptomatic. Those with symptoms may report incomplete evacuation and the
need to apply digital pressure to the posterior vaginal wall or perineum to aid in
evacuation of stool (digitation or splinting). It is important to rule out other causes
of obstructed defecation, because these symptoms are nonspecific. Moreover,
rectocele, enterocele, and perineal descent can result from chronic straining and
increased intra-abdominal pressure caused by other etiologies of defecatory
dysfunction. Defecatory dysfunction related to pelvic organ prolapse can
result from rectocele, enterocele, or perineal descent, either individually or in
combination.
Rectocele, also known as posterior vaginal wall prolapse, is a herniation of
the rectal mucosa through a defect in the fibromuscular layer of the
posterior vaginal wall. These site-specific defects can be transverse or
longitudinal through the inferior, middle, or superior regions of the rectovaginal
fibromuscular layer (38).
Enterocele is a herniation of a peritoneal sac and bowel through the pelvic
floor, typically between the uterus or vaginal cuff and rectum. It is more
common following hysterectomy and retropubic urethropexy. There are two
theories surrounding the formation of an enterocele. The first theory implicates a
defect in the fibromuscular endopelvic fascia of the vagina, allowing peritoneum
and bowel to herniate. The second theory attributes its formation to a support
defect with full-thickness protrusion, including endopelvic fascia (39). Ultimately,
the mechanism might be attributed to a combination of the two theories because
some support defects are secondary to superior breaks in the anterior and
1818posterior pubocervical and rectovaginal fibromuscular layers.
Patients with rectocele and enterocele may have symptoms of pelvic
pressure, vaginal protrusion, obstipation, fecal incontinence, and sexual
dysfunction. Although associations have been made between defecatory
dysfunction and advanced stages of pelvic organ prolapse, a causal relationship
remains to be established (40,41). Controversy remains as to whether anatomic
herniation is the cause of these symptoms or the effect of underlying colonic
dysfunction, chronic constipation, and straining.
Descending perineum syndrome is defined as descent of the perineum (at
the level of the anal verge) beyond the ischial tuberosities during Valsalva.
Excessive perineal descent was first described in the colorectal literature by Parks
et al. in 1966 (42,43). It occurs as a result of inferior detachment of the
rectovaginal septum from the perineal body. As the condition progresses, the
patient can develop pudendal neuropathy from stretch injury. Perineal descent has
been associated with a variety of defecatory disorders, including constipation,
obstructed defecation, fecal incontinence, rectal pain, solitary rectal ulcer
syndrome, rectocele, and enterocele (44).
Rectal Intussusception
Rectal intussusception or intrarectal prolapse is the circumferential prolapse
of the upper rectal wall into the rectal ampulla but not through the anal
verge. It occurs most often in women in the fourth and fifth decade. The most
common symptoms are obstructive, including incomplete emptying, manual
disimpaction, splinting, pain with defecation, and bleeding. Other symptoms
include fecal incontinence, decreased urge to defecate, inability to distinguish
between gas and feces, and mucus discharge with pruritus ani. Forty-five percent
to 80% of patients with rectal intussusception have a solitary rectal ulcer which
may cause bleeding (45). Intussusception is seen in as many as one-third of
women with defecatory disorders. It has been seen in 20% to 50% of
asymptomatic volunteers on defecography and does not commonly develop into
total rectal prolapse (45).
Functional Motility Disorders
Functional Bowel Disorders
Functional bowel disorders, as defined by the Rome IV Criteria (46), consist of
IBS, FC, functional diarrhea, functional abdominal bloating/distension,
unspecified functional bowel disorder, and opioid-induced constipation. This
section will focus primarily on IBS.
IBS has been estimated to have a prevalence of 10% to 20% and is more
common in women and younger individuals. It accounts for 25% to 50% of
1819all referrals to gastrointestinal clinics. IBS has distinct diagnostic criteria,
including the exclusion of structural or metabolic abnormalities. These patients
often have other gastrointestinal, genitourinary, and mental health concerns,
including gastroesophageal reflux disease, fibromyalgia, headache, backache,
chronic pelvic pain, sexual dysfunction, lower urinary tract dysfunction,
depression, and anxiety. Stressful life events may correlate with the onset and
exacerbation of symptoms. A detailed history frequently reveals a history of
abuse. Diagnostic Criteria for IBS include recurrent abdominal pain, on average,
at least 1 day per week in the last 3 months, associated with 2 or more of the
following criteria: (1) related to defecation; (2) associated with a change in
frequency of stool; and (3) associated with the change in form (appearance) of
stool. The criteria must be fulfilled for the last 3 months with symptom onset at
least 6 months before diagnosis (Table 31-5). Specific criteria allow for
classification of IBS into constipation-predominant (IBS-C), diarrheapredominant (IBS-D), mixed bowel habits (IBS-M) and unclassified (IBS-U)
as outlined in Table 31-3. The constipation variant is most commonly associated
with defecatory dysfunction, whereas the diarrhea variant causes fecal
incontinence. The Rome IV Criteria has a sensitivity and specificity of 62.7% and
97.1% for IBS, respectively (47).
Table 31-5 Irritable Bowel Syndrome (C1) (46)
Diagnostic Criteriona
Recurrent abdominal pain, on average, at least 1 day per week in the last 3 months,
associated with 2 or more of the following criteria:
1. Related to defecation
2. Associated with a change in frequency of stool
3. Associated with a change in form (appearance) of stool
aCriterion fulfilled for the last 3 months with symptom onset at least 6 months prior to
diagnosis.
Table 31-6 Functional Constipation (C2) (46)
Diagnostic Criteriaa
1. Must include two or more of the followingb:
a. Straining during more than one-fourth (25%) of defecations
b. Lumpy or hard stools (Bristol Stool 1–2) more than one-fourth (25%) of
1820defecations
c. Sensation of incomplete evacuation for more than one-fourth (25%) of defecations
d. Sensation of anorectal obstruction/blockage more than one-fourth (25%) of
defecations
e. Manual maneuvers to facilitate more than one-fourth (25%) of defecations (e.g.,
digital evacuation, support of the pelvic floor)
f. Fewer than three defecations per week
2. Loose stools are rarely present without the use of laxatives
3. Insufficient criteria for irritable bowel syndrome
aCriteria fulfilled for the last 3 months with symptom onset at least 6 months prior to
diagnosis.
b
For research studies, patients meeting criteria for OIC should not be given a diagnosis of
FC because it is difficult to distinguish between the opioid side effects and other cause of
constipation. However, clinicians recognize that these two conditions might overlap.
FC is a term created to unify the definition of constipation (Table 31-6).
Patients with FC should not meet IBS criteria; abdominal pain and/or bloating
may be present but not predominant symptoms (46).
Table 31-7 Functional Defecation Disorders (F3) (37)
Diagnostic Criteriaa
1. The patient must satisfy diagnostic criteria for functional constipation and/or
irritable bowel syndrome with constipation (Tables 31-5 and 31-6)
2. During repeated attempts to defecate, there must be features of impaired evacuation,
as demonstrated by two of the following three tests:
a. Abnormal balloon expulsion test
b. Abnormal anorectal evacuation pattern with manometry or anal surface EMG
c. Impaired rectal evacuation by imaging
Subcategories F3a and F3b apply to patients who satisfy criteria for FDD
F3a. Diagnostic Criteria for Inadequate Defecatory Propulsion
Inadequate propulsive forces as measured with manometry with or without
inappropriate contraction of the anal sphincter and/or pelvic floor musclesb
F3b. Diagnostic Criteria for Dyssynergic Defecation
Inappropriate contraction of the pelvic floor as measured with anal surface EMG or
1821manometry with adequate propulsive forces during attempted defecationb
aCriteria fulfilled for the last 3 months with symptom onset at least 6 months prior to
diagnosis.
b
These criteria are defined by age- and sex-appropriate normal values for the technique.
Functional Defecation Disorders
Functional defecation disorders are divided into dyssynergic defecation and
inadequate defecatory propulsion (colonic inertia). For the purposes of this
chapter, we have included dyssynergic defecation under the structural category of
outlet obstruction; however, Rome IV considers it as a functional disorder (Table
31-7). Both of the functional defecation disorders require the presence of FC
or IBS-C. Tables 31-5 and 31-6 list the criteria for diagnosing these
conditions.
Colonic Inertia/Slow-Transit Constipation
Severe constipation, defined as fewer than three stools per week and
refractory to therapy, is relatively rare; however, these patients frequently
suffer from motility disorders such as global motility disorder and colonic
inertia. Women are more likely to be affected than men. Colonic inertia or
slow-transit constipation is defined as the delayed passage of radiopaque markers
through the proximal colon without retropulsion of markers from the left colon
and in the absence of systemic or obstructive disorders. The cause remains
unclear. Patients with this disorder have impaired phasic colonic motor activity
and diminished gastrocolic reflexes (48,49). Studies on the role of laxatives,
absorption, hormones, psychological abnormalities, and endogenous opioids have
been inconclusive. The literature suggests a possible neurologic or smooth muscle
disorder (49,50). The smooth muscle-specific contractile protein “smoothelin” is
being studied (51). QoL is impaired in patients with obstructive defecation and
colonic inertia, however, those with obstructive defecation are affected to a
greater extent (52).
Fecal Incontinence
The terms anal and fecal incontinence are used interchangeably, but have subtle
differences. Fecal incontinence is defined as the involuntary loss of solid or
liquid stool. Anal incontinence is defined as the involuntary loss of solid or
liquid stool or flatus. Anal incontinence implies transanal pathology, whereas
fecal incontinence may also occur from a fistula. Accidental bowel leakage is a
newer term preferred by patients, that describes the symptom of fecal
incontinence.
1822Sphincter Disruption
In women, obstetric anal sphincter injury is the most common cause of
accidental bowel leakage. The mechanism of injury can be from anatomic
disruption of the anal sphincter complex, pelvic floor denervation, or a
combination of the two conditions. The risk factors for anal sphincter laceration
are primiparity, high birth weight, operative delivery, and episiotomy, especially
midline episiotomy (53–56). There are several other factors that have been
proposed and studied which demonstrate a variable relationship with perineal
laceration or anal sphincter injury (56–58). Studies suggest that women who have
slower labor without the normal deceleration phase, and with late descent of the
fetal head, are more likely to have anal sphincter injuries (57,59). The duration of
the second stage is an independent risk factor for all women, and duration of
pushing greater than 60 minutes is a significant risk factor for anal sphincter
injury in primiparous patients (59). There are limited long-term prospective
studies demonstrating the natural history of anal sphincter injury, pelvic floor
neuropathy, and the progression of these conditions to fecal incontinence. The
literature supports the relationship of early-onset symptoms to sphincter damage
and delayed-onset symptoms to neuropathy (60–62).
Obstetric Trauma
Third- and fourth-degree lacerations at delivery are associated with an
increased risk of fecal incontinence (OR = 2.66 to 3.09) (60,61). The incidence
of clinically documented third- and fourth-degree anal sphincter tears are 0.5%
and 5.9% respectively and have been increasing over the last 10 years (55,63).
This increase is most likely a result of improved diagnosis, as the occult thirdand fourth-degree defects described in 28% to 35% of primiparous women and
44% of multiparous women are not missed by better trained maternity providers.
Patients with occult anal sphincter tears are 8.8 times more likely to have
fecal incontinence (55,64). Both forceps and vacuum-assisted vaginal delivery
significantly increase this risk, with vacuum being less traumatic than forceps
(58). Scheduled cesarean delivery without labor, in contrast with emergency
cesarean delivery, was believed to prevent anal incontinence, but studies argue
against any protective effect with cesarean delivery, irrespective of timing
(65,66). A Cochrane review from 2010 concludes that there is insufficient
evidence to support primary elective cesarean delivery for the purpose of
preserving fecal continence (67). Midline episiotomy is strongly linked to
sphincter damage and fecal incontinence (54,64) and the consequences are
additive when combined with the use of forceps and vacuum. Mediolateral
episiotomy with instrumentation, however, is found to be protective compared to
instrumentation alone (68). A Cochrane review supports the restrictive use of
1823midline and mediolateral episiotomy because of less posterior perineal trauma,
less suturing, and fewer healing complications. There were no differences in
severe trauma, pain, dyspareunia, or urinary incontinence, but there was an
increase in anterior perineal trauma with restrictive use (69). Another study
suggests that if an experienced care provider is not available immediately or
locally, repair of the third- or fourth-degree tear can be delayed for 8 to 12 hours
with no impact on anal incontinence and pelvic floor symptoms (70).
Surgical Trauma
Iatrogenic injury follows obstetric trauma as the second most common cause
of direct sphincter damage. Surgical procedures that have been associated with
fecal incontinence include anal fistula repair, anal sphincterotomy,
hemorrhoidectomy, and anal dilation. Fistulotomy is the most common
procedure that results in fecal incontinence. Rectovaginal or anovaginal
fistulas can develop after obstetric injury, operative complications during pelvic
surgery, and inflammatory bowel disease exacerbations. Fistulas cause fecal
incontinence, and the degree of postoperative dysfunction depends on the location
of the fistula and the amount of sphincter that is disrupted during the surgical
repair. It also depends on the preoperative level of sphincter function and
pudendal nerve function. Anal sphincterotomy to treat painful anal fissures can
lead to incontinence by disruption of rectal sensory innervation and anal cushions
and transection of the anal sphincter (71,72). Hemorrhoidectomy often results in
minor soiling as a result of resection of the anal cushions, which act as the final
mucosal barrier. Similar to sphincterotomy, rectal sensory innervation can be
disrupted, and injury to the IAS can occur during sharp dissection (72,73).
Sphincter Denervation
Idiopathic (primary neurogenic) fecal incontinence results from denervation
of both the anal sphincter and pelvic floor muscles. Denervation injury related
to obstetric trauma accounts for approximately three out of every four cases of
idiopathic fecal incontinence and is the most common overall cause of fecal
incontinence (70,71).
Obstetric Trauma
The two proposed mechanisms of pudendal neuropathy are stretch injury during
the second stage of labor and compression of the nerve as it exits Alcock canal
(74). Established risk factors for pelvic floor neuropathy include multiparity,
high birth weight, forceps delivery, prolonged active second stage, and thirddegree laceration (75,76). Several studies have shown increased pudendal nerve
terminal motor latencies following vaginal delivery, especially after sphincter
1824laceration (55,77,78). Most women will recover function within a few months
postpartum. Others will have evidence of injury several years later, which may
represent the cumulative effects of subsequent deliveries (77,79). However, fecal
incontinence will develop in only a fraction of patients with neuropathy (76).
Descending Perineum Syndrome
Prolonged straining for any reason can cause descending perineum
syndrome. This syndrome is defined as descent of the perineum beyond the
ischial tuberosities during Valsalva (42,43). Pudendal neuropathy results from
stretching and entrapment of the pudendal nerve. This diagnosis is supported by
findings of elongation of the pudendal nerve, prolonged pudendal nerve motor
terminal latency, and decreased anal sensation in women with perineal descent
(80–82). As pudendal neuropathy progresses, it ultimately leads to fecal
incontinence (83,84).
Functional Bowel Disorders
Fecal Incontinence
The Rome III Criteria established well-defined guidelines for functional
causes of fecal incontinence, however these were cumbersome and seldom
used. The Rome IV Criteria (Table 31-8) now uses a more simplified definition
for any recurrent uncontrolled passage of fecal material. Fecal incontinence is
often multifactorial and occurs in conditions that cause diarrhea, impair colorectal
storage capacity and/or weaken the pelvic floor (Table 31-9).
Irritable Bowel Syndrome
The diarrhea variant of IBS is often associated with fecal incontinence and
disordered defecation. The criteria for diagnosis are in Table 31-5.
Functional Diarrhea
The Rome IV Criteria create a unifying definition of diarrhea called
functional diarrhea (Table 31-10). The rationale for the criteria listed in Table
31-10 stems from the variability in patients’ descriptions of diarrhea (37).
Pitfalls for the Pelvic Floor Surgeon
It is sometimes easy to overlook or misinterpret signs and symptoms of
constipation and defecatory dysfunction. Red flags such as unintentional weight
loss, blood in the stool, fever, and iron-deficiency anemia should prompt
further investigation. Any acute change in bowel habits must be evaluated
thoroughly, and malignancy must be considered in the differential diagnosis.
Even in the presence of chronic disease, malignancy must still be excluded.
1825Persistent symptoms after an empiric trial of medical therapy should prompt
further evaluation, including colonoscopy or flexible sigmoidoscopy. It is
possible to mistakenly attribute symptoms of defecatory dysfunction and
constipation to pelvic organ prolapse when prolapse is actually the result of an
underlying bowel disorder. In this case, surgical treatment of prolapse will have
little lasting benefit if the underlying bowel disorder remains untreated.
Table 31-8 Fecal Incontinence (37)
Diagnostic Criteriaa
Recurrent uncontrolled passage of fecal material in an individual with a developmental
age of at least 4 years
aCriteria fulfilled for the last 3 months. For research studies, consider onset of symptoms
for at least 6 months previously with 2–4 episodes of FI over 4 weeks.
Table 31-9 Common Causes of Fecal Incontinence (37)
Anal sphincter weakness
Traumatic: obstetric, surgical (e.g., hemorrhoidectomy, internal sphincterotomy,
fistulectomy) Nontraumatic: scleroderma, idiopathic internal sphincter
degeneration
Neuropathy
Peripheral (e.g., pudendal) or generalized (e.g., diabetes mellitus)
Pelvic floor disorders
Rectal prolapse, descending perineum syndrome
Disorders affecting rectal capacity and/or sensationa
Inflammatory conditions: radiation proctitis, Crohn disease, ulcerative colitis
Anorectal surgery (pouch, anterior resection)
Rectal hyposensitivity
Rectal hypersensitivity
Central nervous system disorders
Dementia, stroke, brain tumors, multiple sclerosis, spinal cord lesions
Psychiatric diseases, behavioral disorders
Bowel disturbances
Irritable bowel syndrome, postcholecystectomy diarrhea
Constipation and fecal retention with overflow
1826aThese conditions may also be associated with diarrhea.
HISTORY AND PHYSICAL EXAMINATION
History
[3] A thorough history and physical examination are critical to the evaluation of
fecal incontinence and defecatory dysfunction. The history of present illness
should focus on the bowel habits, including frequency and consistency of
bowel movements (hard vs. soft, formed vs. unformed, diarrhea vs.
constipation). The duration and severity of symptoms and exacerbating
factors are important to understanding the impact on QoL. Patients should be
questioned about straining with bowel movements, symptoms of incomplete
emptying, and splinting of the perianal region, perineal body, or posterior vaginal
wall to assist with evacuation. They should be asked about the need to perform
digital disimpaction because they are unlikely to volunteer this information. With
respect to fecal incontinence, information should be obtained about leakage with
solids, liquid, and flatus and the ability to discriminate between these different
types of stool (sampling). Similar to urinary incontinence, fecal incontinence can
be stress related, urge related, or may occur without awareness. Questions about
alternating diarrhea and constipation, mucus or blood in the stools, constitutional
symptoms, and changes in stool caliber can help the investigator uncover
systemic and functional etiologies. Finally, it is important to ask about adaptive
behaviors, pad or diaper use, and past and present treatments including surgery,
physical therapy, and medications.
Table 31-10 Functional Diarrhea (C3) (46)
Diagnostic Criteriona
Loose or watery stools, without predominant abdominal pain or bothersome
bloating, occurring >25% of stoolsb
aCriteria fulfilled for the last 3 months with symptom onset at least 6 months prior to
diagnosis.
b
Patients meeting criteria for diarrhea-predominant IBS should be excluded.
A large amount of information can be obtained efficiently through
questionnaires. Validated questionnaires quantify symptoms, which are subjective
in nature, to objectively measure response to treatment. A valuable survey to
assess defecatory dysfunction is the ColoRectal-Anal Distress Inventory
(CRADI), which has been incorporated into the Pelvic Floor Distress
1827Inventory (PFDI) (85). The latter is a useful tool for evaluating symptoms of
prolapse, urinary incontinence, fecal incontinence, voiding dysfunction, and
defecatory dysfunction. Other useful symptom scales and bother scores for fecal
incontinence include the Wexner Score (86), Fecal Incontinence Severity Index
(87), and Fecal Incontinence QoL (FIQoL) Scale (88). The Rome IV Diagnostic
Questionnaire for Adults focuses on clinical diagnoses of IBS, functional
dyspepsia (FD) and FC. Sensitivity was 62.7% for IBS, 54.7% for FD, and 32.2%
for FC. Specificity was 97.1% for IBS, 93.3% for FD, and 93.6% for FC (47).
The medical history, surgical history, family history, and review of systems
should focus on uncovering potential systemic and obstructive disorders shown in
Table 31-1. A complete obstetric history should include the number of
vaginal deliveries, operative vaginal deliveries, or presence of a third- or
fourth-degree laceration, which is critical for patients with fecal
incontinence. Length of the second stage of labor, birth weight, and the use of
episiotomy should be ascertained because they may pose risk factors for sphincter
damage and denervation. A sexual history should be obtained by first asking if the
patient has had any negative sexual experiences. This will allow details regarding
sexual assault, anal penetration, and dyspareunia to be ascertained. Use of overthe-counter, prescription, recreational and illegal drugs, and allergies should be
recorded.
Physical Examination
The evaluation of anorectal dysfunction requires a basic general examination
and a focused abdominal and pelvic examination. The general physical survey
should include a global assessment of mobility and cognitive function. Routine
examination of the abdomen involves inspection, palpation, and auscultation to
rule out the presence of masses, organomegaly, and areas of peritoneal irritation.
This examination should be followed by a detailed evaluation of the vagina,
perineum, and anorectum. The goals of the pelvic examination are to define
objectively the degree of prolapse and determine the integrity of the connective
tissue, neurologic function, and muscular support of the pelvic organs.
Neurologic Examination
Important elements of the neurologic examination are assessment of cranial
nerve function, sensation and strength of the lower extremities, and reflexes
for the lower extremities, bulbocavernosus, and anal wink. These
examinations evaluate the function of the lower lumbar and sacral nerve roots,
recognizing the importance of the second through fourth sacral nerve roots in
pelvic floor dysfunction. The perineal reflexes can be elicited by stroking the
1828labia majora and perianal skin with a cotton-tipped swab. The anal wink,
bulbocavernosus, and cough reflexes all test the integrity of motor innervation to
the EAS (S2–S4). Sensation over the inner thigh, vulva, and perirectal areas
should be tested for symmetry to light touch and pinprick.
Muscle Strength
The integrity of the pelvic floor muscles should be assessed at rest and with
voluntary contraction to determine strength, duration, and anterior lift. The
insertions of the puborectalis and pubococcyguous muscles should be
checked for avulsion, which presents as asymmetry. Palpation allows
assessment of tenderness, strength and ability to relax these muscles. Several
standardized systems have been described to objectively measure muscle strength
including manual palpation and scoring of Kegel strength on a scale of 1 through
5, but none has been accepted as a standard (89). The puborectalis muscle should
be readily palpable posteriorly as it creates a 90-degree angle between the anal
and rectal canals. Voluntary contraction of this muscle “lifts” the examining
finger anteriorly toward the pubic rami. An intact EAS muscle that has decreased
tone and contractility often indicates pudendal neuropathy. Neuropathy affecting
the puborectalis can be recognized by an obtuse anorectal angle and weak
voluntary contraction. Similar to the urethral axis, the anorectal angle can be
tested using a cotton-tipped swab, although this test is rarely performed.
Deflection is measured in the supine position at rest, with strain, and with
squeeze.
Vaginal Support
The salient points of pelvic organ prolapse (see Chapter 30) for patients with
defecatory dysfunction are the support of the vaginal apex, posterior wall,
and perineal body, although some experts believe anterior wall defects can
affect defecatory dysfunction. The posterior wall is assessed while supporting
the vaginal apex and anterior wall with a split speculum. This permits the
examiner to focus on identifying specific locations of rectovaginal fascial defects.
A rectovaginal examination aids in identification of defects in the rectovaginal
fascia or perineal body. Loss of vaginal rugation has been reported overlying the
site of a rectovaginal fascial tear (90). This technique is especially useful for
enteroceles, which have a smooth, thin epithelium over the enterocele sac or
peritoneum.
Normally, the perineum should be located at the level of the ischial
tuberosities, or within 2 cm of this landmark. A perineum below this level, either
at rest or with straining, represents perineal descent. Subjective findings of
perineal descent include widening of the genital hiatus and perineal body, and
1829flattening or a convex intergluteal sulcus. Women with perineal descent tend to
have less severe stages of pelvic organ prolapse based on the Pelvic Organ
Prolapse Quantification (POP-Q) staging system (91) because it measures
descent from the hymenal ring. Consequently, an increase in the length of the
perineal body and genital hiatus with straining suggests perineal descent. The
degree of perineal descent can be measured objectively with a St. Mark’s
perineometer, although a thin ruler placed in the posterior introitus at the level of
the ischial tuberosities can be used. Descent is measured as the distance the
perineal body moves when the patient strains. Although pelvic floor fluoroscopy
is the standard technique for measuring perineal descent, this technique is most
useful in patients with symptoms of severe defecatory dysfunction and evidence
of perineal descent on pelvic examination.
Anorectal Examination
Visual and digital inspection of the vagina and anus will help to identify
structural abnormalities such as prolapse, fistulas, fissures, hemorrhoids, or
prior trauma. A rectovaginal examination provides useful information regarding
the integrity of the rectovaginal septum and can demonstrate laxity in the support
of the perineal body. The rectovaginal examination is helpful in the diagnosis of
enteroceles, which can be felt as protrusion of bowel between the vaginal and
rectal fingers with straining. Digital rectal examination should be performed at
rest, with squeeze, and while straining. The presence of fecal material in the anal
canal may suggest fecal impaction or neuromuscular weakness of the anal
continence mechanism. Circumferential protrusion of the upper rectum around the
examining finger during straining suggests intussusception, which often occurs in
combination with laxity of the posterior rectal support along the sacrum.
The integrity of the EAS and puborectalis muscle can be evaluated by
observation and palpation of these structures during voluntary contraction.
Evidence of dovetailing of the perianal skin folds and the presence of a perineal
scar with an asymmetric contraction often indicates a sphincter defect. When a
patient is asked to contract her pelvic floor muscles, two motions should be
present: The EAS should contract concentrically, and the anal verge should be
pulled inward. These actions should be apparent on digital rectal examination.
The 90-degree angle created by the puborectalis should be readily palpable
posteriorly and, with voluntary contraction, the examining finger should be lifted
anteriorly toward the pubic rami. Both the puborectalis and EAS should relax
during Valsalva effort. Patients with anismus may experience a paradoxical
contraction of these muscles during straining. Finally, defects in the anterior
aspects of the EAS may be detected by digital examination. The Digital Rectal
Examination Scoring System (DRESS) is a 5-point scale that is quantified during
1830resting and squeeze. A score of 3 is assigned to a normal tone (Table 31-11).
TESTING
Sophisticated diagnostic testing is being used in clinical and research anorectal
physiology laboratories to quantify the function of the colon and anorectum.
Following is a description of these techniques as they relate to the management of
fecal incontinence and disordered defecation.
Table 31-11 The Digital Rectal Exam Scoring System (DRESS) (92)
Resting Score
0 No discernable tone at rest, an open or patulous anal canal
1 Very low tone
2 Mildly decreased tone
3 Normal
4 Elevated tone, snug
5 Very high tone, a tight anal canal, difficult to insert a finger
Squeeze
0 No discernable increase in tone with squeezing effort
1 Slight increase
2 Fair increase but below normal
3 Normal
4 Strong squeeze
5 Very strong squeeze, to the point of being painful to the examiner
Fecal Incontinence
Endoanal Ultrasonography
Endoanal ultrasonography permits accurate imaging of both the IAS and
EAS. It can assess the continuity and thickness of the muscle and is
considered the single best method for detecting anal sphincter defects.
Endoanal ultrasonography is performed using a Bruel–Kjaer (Copenhagen,
Denmark) ultrasound scanner with a 360-degree rectal endoprobe (type 1850)
with a 7 MHz transducer (focal length, 2 to 5 cm) housed within a plastic cone
(Fig. 31-1). On images from this device the normal IAS is a continuous
hypoechoic band of smooth muscle surrounded by the thick echogenic layer of
the striated EAS. A sphincter defect appears as a disruption in these muscle
bands. Location and severity of the defect can be described by circumferential
1831distance in degrees, percent thickness, and distance from the anal verge (Fig. 31-
2). Measurements are usually taken in the proximal, middle, and distal anal canal.
It is important to recognize the physiologic split in the proximal EAS as it merges
with the puborectalis muscle of the levator ani. Misinterpretation of this finding as
a sphincter defect can lead to inaccurate diagnosis. The puborectalis muscle
appears as a U-shaped or V-shaped thick echogenic layer outside the IAS and
contiguous with the EAS in the proximal anal canal.
FIGURE 31-1 Bruel–Kjaer (Copenhagen, Denmark) ultrasound probe (type 1850)
with a 7 MHz transducer (focal length, 2 to 5 cm) housed with a plastic cone.
Magnetic resonance imaging (MRI) is an alternative to endoanal ultrasound
that is equally effective at diagnosing sphincter defects, and with the use of a
vaginal or rectal coil, better at imaging fistulae. Because MRI is more expensive,
endoanal ultrasound is the preferred imaging modality for evaluation of the
sphincter complex, and MRI use is largely investigational or for diagnosis of
fistulae. It may be beneficial in cases in which endoanal ultrasonography results
are inconclusive or the quality of the study is poor.
Electromyography
Electromyography (EMG) is useful to evaluate neuromuscular integrity of
the EAS and pelvic floor muscles following a traumatic injury such as
childbirth (93). This technique measures the electrical activity arising in muscle
fibers during contraction and at rest. Different types of electrodes may be
employed, including surface electrodes, concentric needle electrodes, and singlefiber electrodes. Surface electrodes are less invasive because they are applied near
or within the anal canal, but are limited to recording basic anal sphincter activity.
This technique often is used in conjunction with biofeedback therapy. Concentric
needle electrodes are most commonly used in anorectal physiology laboratories to
1832selectively survey an individual muscle’s activity. Insertion of the thin needle-like
cannulas containing steel wire electrodes can be painful. The smaller single-fiber
EMG electrodes are used to record the activity of single muscle fibers, which can
be quantified to calculate fiber density. Following denervation injury, increased
muscle fiber density occurs during reinnervation. Thus, single-fiber EMG can
provide indirect evidence of neurologic injury by mapping the EAS and
identifying injured areas. This technique is rarely used in clinical practice as
endoanal ultrasonography offers better patient comfort and more reliable results
than EMG.
Motor nerve conduction studies provide another means of measuring
pelvic floor neuropathy. The axon of a nerve is stimulated, and the time it takes
the action potential to reach the muscle supplied by the nerve is recorded. The
delay between stimulation and the muscle response is called the nerve latency.
Pudendal nerve terminal motor latency (PNTML) can be determined by
transrectal stimulation of the pudendal nerve using a St. Mark’s electrode (94). A
nerve stimulator is mounted on an examination glove at the fingertip (Fig. 31-3)
and positioned transrectally over each ischial spine. A stimulus of up to 50 mV
over a duration of 0.1 milliseconds is applied, and the latency of the EAS muscle
contraction is measured. A value of 2.2 milliseconds or less is considered normal.
Early studies of PNTML suggested that bilateral pudendal neuropathy tended to
occur more frequently in older women (95). A study evaluating normative values
for pudendal and perineal nerve latencies observed increased latencies with
increased age (96). Prolongation of the PNTML is indicative of damage to that
nerve or the presence of a demyelinating condition. Pudendal nerve function has
prognostic value in the surgical repair of traumatic sphincter injuries (96) and
may be useful in preoperative counseling.
18331834FIGURE 31-2 A: Endoanal ultrasound image from the distal anal canal demonstrating
defects in the internal sphincter from 10 to 3 o’clock and the external sphincter from 10 to
2 o’clock. B: Endoanal ultrasound image from the middle anal canal demonstrating
defects in the internal sphincter from 12 to 2 o’clock and the external sphincter from 10 to
1 o’clock. C: Endoanal ultrasound image from the proximal anal canal demonstrating
an intact IAS and a normal physiologic split in the external sphincter.
Anal Manometry
Anal manometry is used to quantify function of the anal sphincter
mechanism. Water-perfused manometry catheters or water-filled balloons are
most often used to measure anal canal pressures. Resting anal canal pressures
reflect IAS function, and pressures in the lower anal canal during maximal
voluntary contraction reflect EAS function. Vector analysis can be used to detect
asymmetry within the anal sphincter. Anal manometry can provide indirect
evidence of sphincter injury; low resting tone indicates IAS injury, and decreased
maximum squeeze pressures indicates EAS injury. However, anal pressures are
influenced by a variety of factors, including tissue compliance and muscular tone.
Consequently, anal manometry results are difficult to interpret and correlate
poorly with the specific anatomic defect. Interpretation is further complicated by
the wide variation of normal pressure values that change with age and parity.
Significant overlaps occur between manometric values for incontinent patients
and those without incontinence. Thus, anal manometry may be of limited value in
the evaluation and treatment of anal sphincter defects and fecal incontinence.
1835FIGURE 31-3 St. Mark’s electrode used for measuring pudendal nerve motor
terminal latency. The stimulating electrode is on the fingertip, and the receiving electrode
is on the proximal finger near the knuckle.
Proctoscopy and Flat Tire Test
Proctoscopy has an important role in the evaluation of fecal incontinence. It can
be performed independently or during colonoscopy, flexible sigmoidoscopy, and
flat tire test. Proctoscopy can detect anorectal pathology, such as prolapsing
hemorrhoids, intussusception, ulcerative or radiation proctitis, or a solitary
rectal ulcer. The flat tire test is useful when a rectovaginal or colovaginal fistula
is suspected but cannot be visualized on routine office evaluation or MRI. This
test usually is performed under anesthesia but can be done in the office setting.
Saline or water is placed in the vagina with the patient in Trendelenburg position.
Air is instilled into the rectum using a proctoscope or rigid sigmoidoscope.
Vaginal retractors provide visualization of the posterior vaginal epithelium and
vaginal apex. Observation of bubbling into the vaginal fluid confirms the
diagnosis and location of a rectovaginal or colovaginal fistula. The rectal site of
the fistula is usually visible, depending on the size and location of the fistula and
the quality of the bowel preparation.
Disordered Defecation
1836Sitzmark Study
Colonic transit studies are useful to evaluate colonic motility, and are
performed using serial abdominal radiography after the patient ingests
radiopaque markers. The purpose is to differentiate between normal-transit,
slow-transit and outlet dysfunction categories of primary constipation (97).
Patients are asked to follow a high-fiber diet over the test period and avoid the use
of laxatives, suppositories, or enemas. A capsule containing 20 to 24 markers is
ingested initially, and abdominal radiography is performed either daily or on the
4th day, the 7th day, and every 3 days thereafter until all the markers are gone.
Segmental transit times are then calculated using a mathematical formula. Colonic
transit study results are used to classify patients with constipation into delayed
transit, normal transit, and outlet obstruction. After day 6, there should be fewer
than five markers remaining in the colon. With slow transit, more than five
markers are scattered throughout the colon. With outlet obstruction, more than
five markers are in the rectosigmoid region, and transit is normal throughout the
rest of the colon.
Pelvic Floor Fluoroscopy and Magnetic Resonance Imaging
Pelvic fluoroscopy permits dynamic radiologic evaluation of pelvic floor and
anorectal anatomy and physiology. It is particularly useful in obstructive
defecation disorders, such as intussusception, rectocele, enterocele, anismus,
and perineal descent. The patient is placed on a radiolucent commode, and
contrast material is instilled into the rectum. The addition of vaginal, bladder, and
oral contrast material is helpful diagnostically when multicompartmental prolapse
is suspected. A series of lateral still images or continuous imaging using
videography are made with fluoroscopy while the patient is at rest, during
defecation, and with contraction of the anal sphincter. Similar films can be
obtained for evacuation of the bladder. Pelvic fluoroscopy has many names,
including defecography, defecating proctography, defecating cystoproctography,
and colpocystoproctography, depending on the technique used. The
measurements obtained include size of the rectal ampulla, length of the anal
canal, anorectal angle, puborectalis motion, and pelvic floor descent. Severity and
location of prolapse and pelvic floor descent is quantified in relation to the
pubococcygeal line. Pelvic fluoroscopy is superior to physical examination for
diagnosing enterocele (98,99), and this technique has the advantage of being able
to distinguish enteroceles from sigmoidoceles. Rectosphincteric dyssynergia may
be present when the patient experiences incomplete relaxation of the puborectalis
muscle during rectal evacuation, the anorectal angle is preserved, and there is
incomplete emptying. Pelvic fluoroscopy is considered the definitive test for
diagnosing intussusception (91,99), and it is the preferred technique for
1837quantifying perineal descent. Dynamic MRI with luminal contrast is an
imaging modality similar to pelvic fluoroscopy. Its ability to detect prolapse is
similar to that of fluoroscopy, but MRI can visualize pelvic floor musculature and
soft tissue, giving it the advantage of detecting ballooning of the levator muscles
and levator ani hernias. The supine position of the testing is a drawback; however,
there are isolated reports of upright dynamic MRI using open scanners that show
results comparable to fluoroscopy for detection of anorectal pathology (100).
Fluoroscopy and dynamic MRI can be used in situations involving severe
multicompartmental prolapse or in which the severity of the symptoms is
disproportionate to examination findings.
Anal Manometry
Anal manometry is useful to evaluate obstructed defecation, through
determination of maximum resting pressure, maximum squeeze pressure,
rectal sensation and compliance, and the presence of an intact rectoanal
inhibitory reflex. With disordered defecation, it can be used to diagnose
Hirschprung disease and anismus. The addition of surface EMG to document
relaxation helps exclude anismus as a cause of obstructed defecation. Failure of
the anal sphincter to relax with defecation and increased electrical activity of the
EAS and puborectalis are seen in patients with anismus. In contrast, there should
be no increase in the electrical activity measured by surface electrodes for patients
with Hirschprung disease. A rectal balloon expulsion test can be of assistance in
the evaluation of rectal emptying and may be valuable during physiotherapy for
diagnosing dyssynergic defecation.
Colonoscopy
Standard gastrointestinal evaluation for patients with symptoms of
disordered defecation, and anyone above the age of 50, should include
routine colorectal cancer screening. The lifetime incidence for patients at
average risk is 4.3% in the United States (101). Accepted modalities for screening
include stool-based testing (guaiac-based fecal occult blood test [gFOBT], fecal
immunochemical test [FIT], FIT-DNA) and visualization-based testing
(colonoscopy, computed tomography colonography, flexible sigmoidoscopy +
FIT/gFOBT). Office-based gFOBT, digital rectal examination and barium
enema/double-contrast barium enema are no longer recommended as screening
tests because of low sensitivity and specificity compared with other techniques
(102).
THERAPEUTIC APPROACH TO FECAL INCONTINENCE
1838Treatment of fecal incontinence should focus on nonsurgical options,
including dietary modification, medical therapy, and biofeedback. Any
underlying systemic conditions or gastrointestinal disorders should be treated
before initiating an extensive evaluation for other causes of fecal incontinence. If
symptoms persist, further investigation should be undertaken. If the evaluation
discloses an underlying EAS defect and conservative therapy has been
unsuccessful, it is reasonable to proceed with surgical treatment provided the
patient’s decision is well informed concerning potential benefits and risks.
Following is an overview of treatment options and the efficacy of each
approach. The lack of consistent outcome measures makes it difficult to compare
efficacy among treatments. Some studies base success on strict conformity with
criteria for continence, but the results vary for continence of flatus, liquid, or solid
stool. Other studies base success on more subjective criteria, such as
improvement following treatment. Daily diaries can be maintained, but the results
may be unreliable. Even if a validated symptom survey and QoL scale is
employed, few studies use the same outcome measures.
Nonsurgical Treatment
Nonsurgical management focuses on maximizing the continence mechanism
through alteration of stool characteristics or behavioral modification. Stool
consistency and volume can be manipulated by dietary and pharmacologic means
to achieve passage of one to two well-formed stools per day. The rationale for this
approach is that formed stool is easier to control than liquid stool. Behavior
modification can be employed using bowel regimens that focus on the predictable
elimination of feces. Physical therapy and biofeedback can be useful for
strengthening the continence mechanism.
Pharmacologic Approaches
Dietary Modification and Fiber
Dietary modification for treatment of fecal incontinence frequently involves
avoidance of foods that precipitate loose stools and diarrhea. Common dietary
irritants include spicy foods, coffee, and other caffeinated beverages, alcohol, and
citrus fruits. Avoidance of dairy products or the addition of lactase dietary
supplements is essential for those with lactose intolerance.
The addition of fiber may improve fecal incontinence by functioning as a stoolbulking agent to increase volume and density. The average individual in the
United States consumes less than one-half of the recommended daily fiber intake
(25 to 35 g). Various fiber sources are listed in Table 31-12, with the highest
content found in fiber cereals. It is difficult to consume the recommended daily
1839amount from diet alone, and fiber supplements often are useful. Although the
increased stool volume and density helps many individuals maintain continence,
excessive fiber with inadequate fluid intake may predispose elderly patients to
fecal impaction.
Constipating Agents
Constipating agents have the most value in patients with chronic loose stools
or diarrhea. They can help improve symptoms in patients with fecal
frequency, urgency and incontinence.
Loperamide (Imodium) and diphenoxylate hydrochloride with atropine
(Lomotil) are the most commonly used agents. Loperamide is a synthetic
peripheral μ-opioid receptor agonist that has been shown to prolong transit time
and stimulate anal sphincter function. With either of these agents, careful titration
is recommended to prevent the primary side effect of constipation. It is generally
preferable to begin using 2 to 4 mg of loperamide every other day to daily and
then titrate up to 4 mg three to four times per day. A 4-mg dose before meals has
been shown to increase anal tone and improve continence (103). Use should be
avoided in patients with risk factors for QT prolongation.
Lomotil is started at a dose of 1 to 2 tablets every day or every other day and
titrated up to 1 to 2 tablets three to four times a day as needed. Caution should be
exercised for patients taking other anticholinergic medications. Anticholinergic
side effects include dry mouth, drowsiness, lightheadedness, and tachycardia.
Table 31-12 Fiber Sources
Cereals Fiber Supplements
All-Bran Extra Fiber (1/2 c) 15 g Konsyl (1 tsp) 6.0 g
Fiber One (1/2 c) 14 g Perdiem (1 tsp) 4.0 g
Raisin Bran (1/2 c) 7 g Metamucil (1 tsp) 3.4 g
All Bran (1/2 c) 6 g Maalox w/fiber (1 tbs) 3.4 g
Fruit & Fiber (2/3 c) 5 g Mylanta w/fiber (1 tsp) 3.4 g
Frosted Mini Wheats (1/2 c) 3 g Citrucel (1 tbs) 2.0 g
Breads Vegetables
Whole wheat (1 slice) 2.0 g Lettuce (1 c) 1.4 g
1840White (1 slice) 0.5 g Celery (1) 0.5 g
Bagel (1) 1.0 g Tomato, raw (1) 1.0 g
Modified from Ellerkmann MR, Kaufman H. Defecatory dysfunction. In: Bent AE,
Ostergard DR, Cundiff GW, et al, eds. Ostergard’s Urogynecology. 5th ed. Philadelphia,
PA: Lippincott Williams & Wilkins, 2002:362, with permission.
Codeine is a constipating agent, but should be used with caution, especially in
those with chronic disorders and in elderly patients because of side effects
associated with narcotics, including addiction with prolonged usage and central
nervous system and respiratory depression. With these limitations in mind, there
is evidence of efficacy for codeine in a study of geriatric patients with fecal
incontinence (104). Eighty-two patients were treated based on the underlying
cause: lactulose and enemas for fecal impaction, and codeine phosphate and
enemas for neurogenic fecal incontinence. The rate of cure for fecal incontinence
was 60% in the treatment group versus 32% for controls (P <0.001).
Drugs that act on the anal sphincter may have a role to play in those with fecal
incontinence, including phenylephrine gel, zinc-aluminium ointment and oral
sodium valproate (105). A Cochrane review published in 2013 confirms
improvement in fecal incontinence with medication, but with a higher rate of
adverse effects such as constipation, compared with placebo (105).
Medications for Irritable Bowel Syndrome
Dietary treatment of IBS consists of avoiding foods that are associated with
symptoms, including alcohol, caffeine, sorbitol, and foods that increase gas
production. Although increased dietary fiber or fiber supplementation has been
shown to improve the constipation-predominant form of this illness (IBD-C),
fiber supplementation has little effect on the diarrhea variant associated with fecal
incontinence. The Rome IV collaboration describes dietary fiber supplementation
as a cornerstone of IBS management, although its optimal use can be nuanced
(46). Benefits appear to be confined to soluble (psyllium/ispaghula husk) and not
insoluble (bran) fiber, as the latter can instead exacerbate problems of distention
and flatulence. Low gluten diet and dietary FODMAP (fermentable
oligosaccharides, disaccharides, monosaccharides, and polyols) restriction may
offer some benefit. Pharmacologic therapy is directed toward the predominant
symptom. Agents and rationale for their use are reviewed in the Rome IV papers
(46) (Table 31-13), and some are reviewed here.
Loperamide and Lomotil tend to be useful first-line agents for treating diarrhea.
Tricyclic antidepressants improve abdominal discomfort and are valuable in
diarrhea-predominant patients because of their constipating effect. The serotonin
1841type 3 (5HT3) antagonist alosetron (Lotronex) has been approved by the U.S.
Food and Drug Administration (FDA) for the treatment of severe diarrheapredominant IBS refractory to treatment. It has shown improvement in global
assessment measures, but its use is limited because of multiple isolated case
reports of ischemic colitis. The recommended dose is to begin at 0.5 mg once or
twice daily. It does not appear to be effective for the spastic-pain variant of IBS.
Ondansetron and ramosetron appear effective in the treatment of IBS-D.
Anticholinergics (dicyclomine, hyoscyamine) and antispasmodics (mebeverine,
pinaverine) are targeted at the pain and bloating symptoms but may be useful for
the diarrhea variant because of their constipating side effects. Studies comparing
medications with anticholinergic properties show inconclusive results with only
modest benefits. Anticholinergic agents typically used for overactive bladder have
not been well-studied in the fecal incontinence/diarrhea population, but
anecdotally may have dual benefit in patients with both problems.
A study of tolteridine in 36 healthy subjects for 6 days compared to placebo
examined bowel effects using habits recorded by diaries and concluded that
tolterodine did not significantly affect stool consistency or ease of defecation at
the therapeutic dose used to treat overactive bladder (106). Tolteridine is a
nonselective muscarinic antagonist and is known to have a lower incidence of
constipation compared to other anticholinergic agents used for overactive bladder,
which may be M3 selective.
Table 31-13 Laxatives and Other Treatments of Disordered Defecation/Functional
Constipation/IBS-C (46)
Agent Adult Dose Onset of
Action
Side Effects
Bulk-forming soluble fiber
Natural
(psyllium)
up to 30 g/d in
divided doses
12–72
hrs
Impaction above strictures
Synthetic
(methylcellulose)
4–6 g PO 12–72
hrs
Fluid overload
Emollient laxatives
Docusate salts 50–500 mg PO 24–72
hrs
Skin rashes
Mineral oil 15–45 mL PO 6–8 hrs Decreased vitamin absorption
1842Hyperosmolar/osmotic laxatives
Polyethylene
glycol
17–34 g/day 1 hr Abdominal bloating
Lactulose 15–60 mL PO 24–48
hrs
Abdominal bloating
Sorbitol 120 mL 25%
solution PO
24–48
hrs
Abdominal bloating
Glycerine 3 g suppository 15–60
min
Rectal irritation
5–15 mL enema 15–30
min
Rectal irritation
Sodium
phosphate
120 mL enema 15-60
min
Electrolyte derangement in
elderly
Saline laxatives
Magnesium
sulfate
15 g PO 0.5–3
hrs
Magnesium toxicity, (caution
in low eGFR)
Magnesium
phosphate
10 g PO 0.5–3
hrs
Magnesium
citrate
200 mL PO 0.5–3
hrs
Chloride channel activators
Lubiprostone 8 μg PO BID–
24 μg BID
Nausea, diarrhea
Guanylate cyclase C agonists
Linaclotide 145 μg–290 μg
PO daily
Diarrhea
Plecanatide 3 mg PO daily Diarrhea
Serotonin 5-HT4 Receptor Agonist
Prucalopridea 1–4 mg/day PO Transient headaches, nausea,
diarrhea
1843Stimulant laxatives
Castor oil 15–60 mL PO 2–6 hrs Nutrient malabsorption
Diphenylmethanes
Phenolphthalein 60–100 mg PO 6–8 hrs Skin rashes
Bisacodyl 30 mg PO 6–10
hrs
Gastric irritation
10 mg PR 0.25–1
hr
Rectal stimulation
Anthraquinones
Cascara sagrada 1 mL PO 6–12
hrs
Melanosis coli
Senna 2 mL PO 6–12
hrs
Degeneration of Meissner
and Auerbach plexuses
Aloe
(Casanthrol)
250 mg PO 6–12
hrs
Danthron 75–150 mg PO 6–12
hrs
Hepatotoxicity (w/docusate)
aNot currently available in the United States.
PO, by mouth; PR, per rectum.
From Wald A. Approach to the patient with constipation. In: Yamada T, ed. Textbook of
Gastroenterology. 3rd ed. Philadelphia, PA: Lippincott Williams & Wilkins, 1999:921,
with permission.
Table 31-14 Agents for the Management of Functional Diarrhea/IBS-D/Fecal
incontinence (46,114)
Type of Laxative Adult Dose Side Effects
Bulk-forming laxatives
Natural (psyllium) up to 30 g/day in divided doses Impaction
above
strictures
Synthetic 4–6 g PO Fluid
1844(methylcellulose) overload
µ-Opioid agonist
Loperamide 2–4 mg po; titrate up to 16 mg/day prn
Diphenoxylate/atropine 5 mg QID until control achieved
(maximum 20 mg/day); maintenance
may be lower
Bile salt sequestrants
Cholestyramine 9 g BID–TID Bleeding
(high
chronic
doses)
Colestipol tablets 2 g daily–BID
Colesevelam 625 mg daily–BID
Probiotics Multiple products available
Antibiotics
Rifaximin 550 mg po TID × 14 days
Serotonin 5-HT4 receptor
agonist
Alosetron 0.5–1 mg po daily–BID Ischemic
colitis risk
Ondansetron 4–8 mg TID
Ramosetron 5 μg daily
Mixed opioid agonists/antagonists
Eluxadoline 100 mg BID
Enhancement of anal sphincter tone
Phenylepinephrine gel, sodium valproate, zinc-aluminum ointment, L-erythro
methoxamine gel
Barrier creams
1845Zinc oxide, calmoseptine ointment, alkagin powder, aquaphor ointment
Antispasmodic agents may be of value and are available in many countries but
are not approved for use in the United States. Additional 5HT3 antagonists and
5HT4 antagonists are under development and are approved for use in Europe but
not in the United States. Most studies are poorly designed and difficult to interpret
because of a high placebo response rate that often exceeds 30% (107,108).
Finally, patients with functional diarrhea and a previous cholecystectomy may
find benefit from bile salt sequestrants such as cholestyramine, colestipol, and
colesevalam (Table 31-14).
Behavioral Approaches
Biofeedback
Biofeedback can be an effective therapeutic modality provided patients are
motivated and comprehend instructions. Three main modalities have been
described: rectal sensitivity training (afferent), strength training (efferent), and
coordination training. Afferent training focuses on improving sensation in the
anorectal canal through recruitment of adjacent neurons to decrease the sensory
threshold of volume stimulation. The goal of this training is to enhance and
restore anal sensation and the rectoanal inhibitory reflex. Efferent training
enhances and restores voluntary contraction of the EAS, which permits additional
recruitment of motor units and stimulates muscle hypertrophy. These three
methods of training are often combined for maximal therapeutic benefit. The most
common training method uses an intrarectal balloon. The balloon acts to stimulate
rectal distention and provide pressure feedback from coordinated or synchronized
contraction of the pelvic floor muscles. Other techniques focus on strength
training of the EAS alone using anal pressure feedback or EMG or afferent
training alone using an intrarectal balloon without pelvic floor muscle contraction
in response to the stimulus. There are many variations in protocol such as the
number, frequency, intensity, and duration of sessions.
Several studies have been done to evaluate the efficacy of biofeedback for
treatment of fecal incontinence, and several review articles and meta-analyses
have determined the effects of individual treatments and predictors of patient
response to treatment (109–114). The results of all of these studies uniformly
agree that biofeedback and pelvic floor exercises improve fecal incontinence and
have a role in clinical practice. They also agree that the literature is fraught with
methodologic problems and lacks validated outcomes and controls, making it
difficult to directly compare study results.
Biofeedback is an ideal first-line therapy because it offers an effective,
minimally invasive treatment without any reported adverse events.
1846Biofeedback appears to provide a higher probability of successful outcome
than standard medical care for treating functional fecal incontinence (67%
vs. 36%, respectively, P <0.001) (109).
Combined biofeedback and electrical stimulation may be the best secondline treatment for fecal incontinence. A Cochrane review of biofeedback and
exercises for treatment of fecal incontinence found 21 eligible studies with a total
of 1,525 participants (115). The authors concluded that biofeedback and electrical
stimulation may enhance treatment outcomes compared to either individual
treatment alone. Transanal electrical stimulation may be more beneficial than
vaginal exercises for women with fecal incontinence after childbirth. A systematic
review and meta-analysis published in 2013 identified 128 studies examining
electrical stimulation and biofeedback for the treatment of fecal incontinence.
Twenty-three observational studies and 13 RCTs were included. Outcomes varied
from remission, response, or disease-related QoL on validated scales. Electrical
stimulation alone was inferior to control (i.e., pelvic floor exercises) (RR 0.47, CI
0.13–1.72), whereas biofeedback alone was superior to control (RR 2.35, CI
1.33–4.16) for symptom improvement. Combination of biofeedback and electrical
stimulation together compared to each monotherapy alone was superior. The
authors concluded that higher-quality randomized controlled trials showed more
significant differences between treatment groups, and support electrical
stimulation plus biofeedback as the optimal second-line treatment for fecal
incontinence after dietary and medical management (116).
There are no clear indicators to predict which patients will benefit from
biofeedback. Potential factors include age, duration and severity of
incontinence, prior treatments or surgery, and severity of neurologic or
physical damage. Controversy exists as to whether response to biofeedback is
dependent on the presence of a structurally intact anal sphincter or normal
pudendal nerve function (115,116). There continues to be a need for welldesigned controlled trials using validated symptom surveys and QoL instruments.
More objective measures are desirable, and studies should carefully document
duration of treatment and length of follow-up.
Bowel Regimens
The goal of bowel regimens is to achieve predictable elimination of feces. This
can be accomplished by using the gastrocolic reflex and by dietary and
pharmacologic means. Defecation immediately following meals involves the
physiologic response of the gastrocolic reflex to facilitate predictable emptying.
The strength of the gastrocolic reflex varies among individuals and may be
hypoactive or hyperactive with certain systemic disorders, such as diabetes and
multiple sclerosis. This technique can be especially useful in the morning to give
1847the individual freedom from fecal incontinence throughout the day. The use of
suppositories or enemas in the morning or at night in conjunction with the
gastrocolic reflex may provide further relief of daytime symptoms. The goal is to
leave the rectum empty between evacuations. Enema use, typically once or twice
daily, should be titrated to the patient’s baseline colonic activity. Regular
toileting is effective in institutionalized elderly patients with fecal
incontinence caused by overflow incontinence from fecal impaction. The use
of cone-tip colostomy-irrigation catheters is reserved for patients in whom other
therapeutic modalities have failed. These catheters avoid the risk of rectal
perforation and provide a dam to prevent efflux of the irrigating solutions
(117,118).
Barrier Devices
First described in the 1980s, barrier devices for fecal incontinence may be an
appropriate option for some patients (119). There is a variety of available
plugs, all with the goal to block the escape of stool. They were initially designed
for fecal incontinence in patients with neurogenic fecal incontinence, but can be
used in any patient. Anal plugs are disposable inserts that sit in the anal canal and
may be left in for a maximum 12 hours. A Cochrane review of four studies
suggests that if tolerated, anal plugs are can be successful in maintaining fecal
continence. High discontinuance rates (35%) occur as a result of rectal discomfort
with these devices. Higher satisfaction was reported in the polyurethane plug than
in the polyvinyl-alcohol plug groups (120). The American Gastroenterology
Association clinical practice update reviews other devices such as anal insert
devices (available in the United States) and vaginal inserts with pumps (118). The
LIFE Study published in 2015 evaluated the effectiveness and safety of a vaginal
bowel-control device and pump system, Eclipse (Pelvalon, Sunnyvale, California)
in 61 women. At one month, intention-to-treat success was 79% and over 85%
considered bowel symptoms “much better” or “very much better.” There were no
serious adverse events and the most common occurrence was pelvic pain (22.7%),
mostly occurring during the fitting period (121). Controlled studies of longer
duration are needed to fully assess barrier devices as safe and effective treatment
options, and to define the subset of patients for whom they are effective.
Perianal Bulking Agents
The purpose of injecting a biomaterial into the anal canal is to augment anal
canal coaptation and treat incontinence. Dextranomer microspheres in
nonanimal-stabilized hyaluronic acid (NASHA Dx) is the only FDA-approved
perianal bulking injection agent available. In a randomized-controlled study of
206 patients, 52% in the NASHA Dx group and 31% in the sham injection control
1848group had improvement based on validated scales from baseline at 6 months (OR
2.36) (122). Eleven percent experienced complete continence and the majority
needed two injections to achieve success. There were several criticisms raised
about this study, including that patient selection should have been limited to those
with passive incontinence and low anal canal pressures, and should have included
anorectal sensory or motor function testing (123). Potential complications
included abscess, proctalgia, and rectal hemorrhage.
Surgical Treatment
[4] In general, surgical treatment should be considered after conservative
measures have failed. Although there may be exceptions to this principle, most
surgeons follow this recommendation because of the poor long-term outcomes
and high complication rates associated with surgery for fecal incontinence. The
American Gastroenterology Association proposes a step-wise approach to the
management of fecal incontinence starting with the least to most invasive (Fig.
31-4).
1849FIGURE 31-4 Step-wise approach to the management of fecal incontinence (American
Gastroenterology Association) (118).
Neuromodulation
Sacral Nerve Root Stimulation
Sacral neuromodulation (InterStim®, Medtronic, Minneapolis, Minnesota, USA)
was approved by the U.S. FDA for treatment of urinary urge incontinence in 1997
1850and for nonobstructive urinary retention and urgency in 1999. It has been
employed experimentally for the treatment of fecal incontinence since 1995 and
was approved for this indication in 2011. The exact mechanism of action has not
been fully elucidated. [5] The goal of sacral nerve stimulation is to recruit residual
function of the continence mechanism through electrical stimulation of its
peripheral nerve supply. Initially, indications were confined to patients with
deficient EAS and levator ani function without gross morphologic defects and
intact neuromuscular connections. The acceptable indications have expanded to
include deficiency of the IAS, limited structural defects, and functional deficits of
the IAS and EAS.
Technique
The device is placed exactly the same way as for treatment of urinary
incontinence. Application is performed as a two-stage outpatient surgical
procedure. The first stage involves placement of the electrodes. The electrode is
placed through the S2–S4 foramen using minimally invasive surgical technique.
Proper location is confirmed intraoperatively using fluoroscopy and visualization
of an appropriate pelvic floor muscle response (bellows) with minimal plantar
flexion of the first and second toes, which usually corresponds to S3 stimulation.
An interval testing phase utilizes an external pulse generator that typically lasts 2
weeks. Those with a good response (decrease in fecal incontinence episodes of at
least 50% documented by bowel habit diary) will proceed to the second stage
with a permanent implantable pulse generator (IPG). Typically, only one
electrode is left in place at the end of the second stage. After the permanent pulse
generator is implanted, all adjustments are made using telemetry. The patient has
a basic remote control that enables her to turn the device on or off and adjust the
amplitude of the stimulation. The battery must be replaced every several years.
Efficacy
Data from over two decades on the efficacy of sacral neuromodulation have
reported success rates of up to 54% in the long term (median follow-up 56
months) (124). By the end of 2003, sacral nerve stimulation had been used to treat
more than 1,300 patients with fecal incontinence (125). Despite this large number,
the analysis of the results was limited to several small case series. In all studies,
significant improvements in continence scores lasting up to 99 months occurred.
Most patients experienced at least a 75% improvement in continence scores.
Improvement occurred in the frequency of incontinence episodes, the ability to
postpone defecation, and bowel emptying. Intent-to-treat analysis revealed 80% to
100% therapeutic success. There were significant improvements in QoL measures
using validated measurement scales. Complications occurred in 0% to 50% of
1851patients, with the most common complications consisting of pain at the electrode
or IPG site, electrode migration, infection, or worsening of bowel symptoms. No
permanent sequelae occurred. Effects of anorectal physiology varied among the
published studies, highlighting the fact that the precise mechanism of action
remains unclear.
A Cochrane review of six crossover trials and two parallel trials concluded that
the limited data suggest that sacral nerve stimulation provides improvement in
fecal incontinence but not in constipation (126). In the seminal multicenter trial
conducted to evaluate the efficacy of sacral nerve stimulation for fecal
incontinence, 90% of 133 patients proceeded from temporary to permanent
stimulation. Wexner et al. prospectively followed 120 patients (110 female, 10
male) for a mean of 28 (2 to 70) months. Subjects completed validated QoL
measures and bowel diaries. Success defined as a 50% or greater improvement
and reduction in fecal incontinence episodes per week was achieved in 83% at 1
year and 85% at 2 years. Forty-one percent achieved total continence at 1 year
and mean incontinent episodes decreased from 9.4 to 1.9 per week. The same
group reported an overall 10.8% infection rate (13/120), with 9 occurring within
the first month and 4 occurring after 1 year (127,128). This study served as the
driving force for FDA approval of sacral nerve stimulation for the indication of
fecal incontinence in 2011. Among the early infections, five responded to
antibiotics, one resolved spontaneously, and three were treated surgically. For the
late infections, all four had to be removed. The same group has published longterm follow-up data. Seventy-six of the total of 120 women with sacral nerve
stimulation for chronic fecal incontinence were followed for 5 to 8 years. Eightynine percent reported having greater than 50% improvement and 36% reported
complete continence (129). The most common adverse event in this trial was
infection, at a rate of 10%.
Another large multicenter study of 200 patients revealed decreased severity
scores and improved QoL with sacral nerve stimulation. Loose stool consistency
and low-stimulation intensity were predictive of successful outcomes on
multivariate analysis. Ultrasound findings, manometry, age, and gender did not
impact outcomes (130). Tjandra et al. (131) performed a RCT of 120 subjects
with 1-year follow-up comparing sacral nerve stimulation to best supportive
therapy consisting of pelvic floor exercises, bulking agent, and dietary
manipulation. Fecal incontinence outcomes improved dramatically in the
stimulation group with 47% achieving complete continence. In contrast, there
were no significant improvements observed in the supportive therapy group. This
study suggests that sacral nerve stimulation is the optimal therapy for severe
incontinence (131). Bharucha et al. summarize randomized controlled trials
comparing neuromodulation with medical treatment and percutaneous tibial nerve
1852stimulation (PTNS) (118). In these studies, sacral nerve stimulation was
significantly better than medical treatment but not significantly better than PTNS.
The UK National Institute for Health and Care Excellence (NICE) guidelines
recommend chronic, electrical stimulation of the sacral root as the first-line
surgical intervention for fecal incontinence (132). In the American Society of
Colon and Rectal Surgeons Clinical Practice Guideline for the Treatment of fecal
incontinence, SNS is given a “1B” recommendation: strong recommendation,
moderate-quality evidence (133).
Thus, sacral nerve stimulation appears to be a promising treatment for
fecal incontinence with relatively limited complications. The minimally
invasive nature of this procedure makes it a desirable first-line surgical
option.
Overlapping Sphincteroplasty
[6] Overlapping sphincteroplasty is the procedure of choice for fecal
incontinence caused by a disrupted anal sphincter. Most authorities believe
that an overlapping technique is superior to an end-to-end repair, although there
are few direct comparisons in the literature. The rationale for the overlapping
technique is that a more secure repair can be accomplished by placing sutures
through the scarred connective tissue rather than the sphincter muscle itself. The
idea is that sutures should be less likely to tear through or pull out of connective
tissue than muscle. Therefore, the key component of the overlapping technique is
preservation of the scarred ends of the ruptured EAS for suture placement.
Proponents of the end-to-end repair suggest that the overlapping technique
requires a wider dissection of the EAS that is more likely to result in a muscle
denervation that could impact future function.
Technique
The initial step involves wide mobilization of the ruptured EAS without
excision of the scarred ends of the sphincter. This is accomplished through an
inverted semilunar perineal incision or a transverse incision near the posterior
vaginal fourchette with inferiolateral extension. The latter incision facilitates
repair in patients with concurrent damage to the rectovaginal septal attachment to
the perineal body. Patients with EAS defects have either a band of intervening
fibrous scar tissue between the viable muscular ends of sphincter or a complete
separation with scar tissue present only on the ruptured ends of the sphincter. In
the presence of complete separation of scar tissue, perineal body reconstruction
usually is indicated at the time of repair to restore normal anatomy. A Peña
muscle stimulator aids in identification of the course of the EAS and differentiates
viable muscle tissue from scar tissue. The stimulator can be used to outline the
1853sphincter before incision and during the dissection. It is important to apprise the
anesthesiologist of the stimulator usage so that paralytic agents are avoided.
Excessive lateral dissection of the EAS past the 3 and 9 o’clock positions
potentially jeopardizes the inferior rectal branches of the pudendal nerve
that innervate the EAS. Moderate bleeding is often encountered during this
dissection, making a needlepoint electrocautery useful to maximize hemostasis.
The colorectal literature suggested that identification and reconstruction of the
IAS was not necessary, although more recent experience demonstrates continued
fecal incontinence associated with discontiguous IAS. Consequently, dissection
and repair of the IAS is recommended. Identification of the intersphincteric
groove facilitates dissection of the EAS and IAS. Dissection in this plane is
relatively simple and avoids damage to either sphincter. Defects in the IAS can be
more difficult to visualize because this muscle is intimately associated with the
rectal mucosa. Examination with a finger in the anal canal is often helpful.
The reconstruction begins with repair of an existing IAS defect using a 3-0
delayed absorbable monofilament suture. Next, the EAS defect is repaired with
the primary goal of overlapping at least 2 to 3 cm to ensure adequate bulk of
sphincter muscle encircling the anal canal. The EAS is overlapped using three to
four mattress sutures of 2-0 delayed absorbable monofilament suture through the
distal scar tissue. After the sutures are tied, there should be resistance palpable
with placement of a finger in the anal canal. Copious irrigation is performed
throughout the procedure. Following sphincter repair, a perineal body
reconstruction and rectocele repair should be undertaken, if indicated, to
maximize the normal continence mechanism. Finally, the perineal skin is closed
with interrupted absorbable monofilament sutures. Closure frequently requires
modification of the initial incision because of changes in the perineal architecture
that result from the repair. The most common approach is an inverted Y-shaped
closure of the incision (Fig. 31-5).
18541855185618571858FIGURE 31-5 Overlapping sphincteroplasty procedure. A: Inverted semilunar perineal
incision with the distal ends of the external sphincter outlined using the Peña muscle
stimulator. B: The external sphincter has been dissected, the scar divided in the midline,
and the internal sphincter repaired. C: The external sphincter is overlapped using three
mattress sutures of 2-0 delayed absorbable monofilament suture through the distal scar
tissue. D: The sutures are tied. E: The skin is closed.
Some surgeons recommend the overlapping repair regardless of whether it
is performed immediately postpartum, delayed postpartum, or several years
after obstetric injury. Long-term analyses of RCTs comparing end-to-end and
overlapping sphincter repairs in primary repairs suggest better long-term
outcomes for the overlapping technique (134). Performance of the overlapping
technique immediately postpartum, requires adequate anesthesia, exposure, and
equipment best accomplished in the operating room. This repair lacks the
theoretical advantage of using scar tissue to improve suture holding; however, it
maximizes surface area for scarification of the sphincter ends. For a delayed
postpartum repair, some surgeons recommend waiting 3 to 6 months until
inflammation is resolved and reinnervation is completed. Cessation of
breastfeeding may be beneficial for postoperative wound healing by restoring
normal vaginal estrogen status.
The Cochrane review comparing end-to-end approximation versus overlapping
sphincteroplasty after an acute obstetric injury included six randomized control
trials involving 588 women. Outcomes included reducing subsequent anal
incontinence, perineal pain, dyspareunia and improving QoL (134). Given data
heterogeneity, the literature does not support recommending one obstetric anal
sphincter repair technique over the other, however there were some differences
shown between the two groups. For example, women in the overlapping repair
group from one trial (52 women followed up for 12 months) had less fecal
urgency and lower fecal incontinences scores (135). Another trial showed that
these differences were no longer present at 36 months (136).
Efficacy
Despite the many large series reporting the outcomes of overlapping
sphincteroplasty, almost all are retrospective in nature and lack validated
measures of symptom severity and QoL considerations. Several overlapping
sphincteroplasty series with a total of 891 patients were evaluated from 1984 to
2001. Although the length of follow-up was variable, the results showed good
outcomes in approximately two-thirds of patients (median 67%, range 52% to
83%) (115). None of these studies had long-term outcomes.
Some studies suggest poor long-term outcomes for the overlapping
1859sphincteroplasty.
Short-term outcomes in the first 12 months after sphincter repair are favorable
in up to 85% of patients (137) but failure rates of over 50% are noted by 5 years
(138–141). Rezvan et al. summarized 10 studies on long-term outcomes of
sphincter repair (142). Three of these studies are described here.
In a series of 55 women who underwent overlapping sphincteroplasty for fecal
incontinence secondary to obstetric trauma (138), researchers contacted 47 (86%)
patients by postal questionnaire and telephone interview with a median time since
surgery of 77 months (range 60 to 96 months). The investigators observed less
symptomatic improvement when compared with the results at 15 months
postoperative evaluation. After excluding one patient because of Crohn disease,
eight (17%) failed because they required additional surgery, such as colostomy,
postanal repair, and artificial bowel sphincter. Among the remaining 38 patients,
27 (71%) reported improved bowel control, 5 (13%) were unimproved, and 6
(16%) were worse. No patient was fully continent to solid and liquid stool and
flatus. Only 23 (50%) patients had “good” outcomes defined as not requiring
further continence surgery and fecal incontinence less than once per month.
In another study, investigators contacted 49 (69%) of 71 patients by telephone
interview (141). All underwent overlapping sphincteroplasty with a median
follow-up of 62.5 months (range 47 to 141 months). Only 6 (12%) patients were
totally continent, and another 18 (37%) were continent to liquid and solid stool. In
other words, more than half of the patients had incontinence to liquid or solid
stool. The largest series with long-term follow-up involved contact of 130 (71%)
of 191 patients using a postal or telephone questionnaire (118). The median time
from surgery for respondents was 10 years (range 7 to 16 years). Of those who
responded, 6% had no incontinence, 16% were incontinent of flatus only, 19%
had soiling only, and 57% were incontinent of solid stool. These outcomes were
significantly worse than the previously reported 3-year assessment (143). Despite
the fact that 61% had a poor outcome defined as having fecal incontinence or
requiring additional surgery for incontinence, 62% still considered their bowel
control to be better than before surgery, and 74% were satisfied with the results of
their surgery. Thus, although control may be improved when compared with
preoperative status, continence outcomes do not seem to be maintained at longterm follow-up.
The cause of this deterioration in long-term outcomes is unknown. Possible
explanations include weakening of the muscles with normal aging, repair
breakdown, and underlying nerve damage from either obstetric injury or the
repair itself. A problem with most studies is the lack of a follow-up
ultrasonography to determine if the repair is intact. The effect of pudendal nerve
function on overlapping sphincteroplasty is somewhat controversial. Significantly
1860lower success rates have been shown in a comparison of those with normal
pudendal nerve terminal motor latencies to those with abnormal latencies (63%
vs. 17%, P <0.01) (144). Some studies have confirmed this finding, while others
refute it (138,145). Other factors that may affect outcome include age, duration of
fecal incontinence, size of the defect, and anal manometry results. Recognizing
that an overlapping sphincteroplasty only addresses one aspect of the continence
mechanism helps to put these results into perspective.
Although there are many controversial aspects to overlapping sphincteroplasty,
the literature is in agreement that diverting colostomy is not necessary; bowel
confinement does not improve outcomes (146–149); clinical improvement
correlates with postoperative endoanal ultrasonography results (138,150,151); and
prior sphincteroplasty does not affect outcomes (144,150,152).
Subsequent Deliveries
Multiple studies confirm the impact of anal sphincter laceration during the
first delivery on the risk of a sphincter laceration in a second delivery (153–
160). These studies have calculated odds ratios ranging between 3.8 and 5.9 for a
second sphincter disruption compared to women without prior obstetrical anal
sphincter injury (58). Although higher than in women without a prior injury, the
risk of having a recurrent obstetric anal sphincter injury is the same for a woman
with previous injury as the baseline risk for a primiparous delivery; both around
5% (58,161). The vast majority of women with a third- or fourth-degree tear
(∼ 91%) will not have a recurrent sphincter injury. Therefore, although a history
of prior sphincter laceration increases the risk of recurrent sphincter
laceration, the risk remains relatively small. Nevertheless, the rate of anal
incontinence worsens, especially if she had transient anal incontinence after the
index anal sphincter injury (58). A decision analysis modeling study concluded
that in women with prior obstetrical anal sphincter injury 2.3 elective cesarean
sections would need to be done to prevent one case of anal incontinence, at a cost
of increased maternal morbidity related to cesarean section (162), which many
women will find to be an acceptable risk. It is therefore important to accurately
counsel expectant mothers about their risk of sphincter laceration. Using this
information, they can decide whether the risk of recurrent laceration outweighs
the risk of elective cesarean birth. The risk of subsequent vaginal delivery on
symptoms of fecal incontinence is unknown for women with a repaired anal
sphincter. The presence or absence of pre-existing fecal incontinence, and the
estimated fetal weight, should be considered in counseling for a subsequent
pregnancy. Cesarean section is more advantageous for those women with prior
anal sphincter injury who are symptomatic.
1861Graciloplasty
Surgical reconstruction with a muscle flap is an option in cases that have
insufficient muscle to repair the EAS when all conservative measures have
failed. Insufficient muscle can be caused by trauma, infection, or severe atrophy
that results from denervation injury and congenital disease. Most patients
considering this procedure have already undergone an overlapping
sphincteroplasty that failed. Graciloplasty, first described by Pickrell et al. in
1952 (170), is a skeletal muscle transposition procedure that uses the gracilis to
create a new anal sphincter. There are three suitable muscles for this type of
procedure: the gracilis, sartorius, and gluteus maximus. Ideally, the muscle should
be easily mobilized and transposed but not essential for locomotion or posture.
The sartorius and gluteus maximus are suboptimal because the sartorius receives
segmental vascularization, which restricts rotation, and the gluteus maximus is
important in daily activities such as running, climbing stairs, and rising from a
sitting position. The gracilis is a better choice because it can easily be
mobilized without damage. As the most superficial adductor, it receives
neurovascular supply proximally and has no important independent function.
Technique
Either one long incision or three small incisions are made in the medial thigh. The
gracilis muscle is identified and mobilized toward its insertion onto the medial
aspect of the tibia where the tendon is divided. Anterior and posterior perianal
incisions are made approximately 1.5 cm from the anal verge. Tunnels are
developed in the extrasphincteric space and from the proximal thigh to the
anterior perianal incision. The gracilis muscle is gently delivered to the anterior
perianal incision, guided around the anus to the posterior perianal incision, and
returned to the anterior incision encircling the anal canal. The distal tendon of the
gracilis is passed behind the muscle and anchored to the contralateral periosteum
of the ischium. In cases when there is inadequate length, it can be sutured to the
ipsilateral ischium. This procedure can be performed bilaterally. In patients with a
large rectovaginal fistula or cloaca, a myocutaneous flap can be mobilized and
used to help close the defect. Improvement of fecal incontinence is caused by
passive increase of the resistance of the anal canal by the bulk of the encircling
muscle (Fig. 31-6).
Experimental efforts to improve the efficacy of this procedure have focused on
dynamic graciloplasty, which develops resting tone in the transposed muscle
through the use of an implanted neurostimulator. The intent of the stimulated
graciloplasty is to convert the fast-twitch muscle fibers into slow-twitch muscle
fibers, which are more fatigue resistant. Initially, implantation of the pacemaker
was performed at 6 weeks after the graciloplasty, but now most are performed
1862concomitantly. Stimulation can be applied directly to the obturator nerve or
intramuscularly to the nerve branches inside the muscle. The muscle is stimulated
at a cyclic frequency, with gradual increases every 2 weeks. After 2 months,
continuous stimulation is performed. Stimulation is adjusted to maintain tonic
contraction around the anus, and it is interrupted or turned off to defecate.
Efficacy
The dynamic graciloplasty restores fecal continence in 42% to 85% of patients
(171). However, given the high rates of morbidity, this procedure is rarely
pursued. Complications include surgical-site infection, rectal pain, rectal injury,
stimulator malfunction and device erosion, and the rate of postsurgical obstructive
constipation is as high as 50% (172).
An exhaustive review of the literature identified 37 articles of patients
undergoing dynamic graciloplasty (171). Most of these articles were case series,
and there were no randomized trials or cohort studies evaluating safety and
efficacy. Mortality rate was 1% (range 0%–13%, 95% CI, 1%–3%) after
excluding cancer deaths. There was a high rate of morbidity (1.12 events per
patient). Thus, most patients will have at least one adverse event, and several will
have multiple complications. There is a very high reoperation rate. The most
common complications were infections (28%), stimulator and lead faults (15%),
and leg pain (13%). Satisfactory continence was achieved 42% to 85% of the
time, although satisfaction was not defined consistently across studies. The
authors concluded that dynamic graciloplasty appeared to have equal or better
efficacy than colostomy but carried a higher morbidity rate. Two review articles
state this procedure is no longer being performed routinely in the United States
(113,118).
Artificial Sphincter
The artificial anal sphincter is an alternative to a graciloplasty. This is a
modification of the device originally designed to treat urinary incontinence. The
current device is the Acticon® Neosphincter (American Medical Systems,
Minnetonka, Minnesota, USA). The indications for its use are similar to those for
the graciloplasty. A silastic inflatable cuff is placed around the native sphincter to
occlude the anal canal. A pressure-regulating balloon containing radio-opaque
solution is situated in the retropubic space, and a control pump is positioned in the
labia majora. Activation of the control pump deflates the cuff, permitting
defecation (see Fig. 31-7).
Technique
Implantation of the artificial anal sphincter is performed, similar to the
1863graciloplasty, through perianal tunnels.
Efficacy
An extensive review of the literature summarized 13 case series and one case
report from 1996 to 2003. There were no randomized trials or cohort studies
(163). The largest series consisted of 112 patients (164). Explantation was
required in 17% to 41% of patients. Reasons for explantation included infection,
erosion, device malfunction, pain, incontinence, and dissatisfaction, with infection
being the most common. Surgical revision was necessary in 13% to 50% of the
reports. Almost everyone had at least one adverse event, and more than one-third
of these events required surgical intervention. Reasons for surgical revision were
similar to those for explantation. Rates of fecal impaction ranged from 6% to
83%. All studies recorded statistically and clinically significant improvement in
continence scores for patients with a functional artificial sphincter; however, most
did not report the continence status for those in whom the device was explanted.
The proportion of patients with a functional device ranged from 49% to 85%. The
authors concluded that there is insufficient evidence on the safety and
effectiveness of the artificial sphincter for fecal incontinence. In 2011 this same
group published their experience over one decade (mean follow-up >5 years) in
52 patients. All patients had failed conservative management and undergone
preoperative assessment with anal endosonography, manorectal manometry, and
physiologic testing. Mean follow-up was 64.3 months. Fifty percent of patients
required revision surgery after a mean of 57 months, with the most common
indication being leaking from the cuff as a result of a microperforation. Twentyseven percent of patients required explantation, with the most common indication
being infection. In the 35 patients with an activated device in situ, there was a
significant improvement in median FIQoL Scores compared to those with devices
explanted or deactivated. The authors conclude that favorable long-term results
can be achieved with careful patient selection, meticulous surgical technique and
dedicated surveillance (165).
18641865FIGURE 31-6 Graciloplasty. A: The gracilis muscle is identified and mobilized toward
its insertion onto the medial aspect of the tibia where the tendon is divided. B: Anterior
and posterior perianal incisions are made approximately 1.5 cm from the anal verge. The
muscle is then tunneled around the extrasphincteric space circumferentially. The distal
tendon is passed behind the muscle and anchored to the contralateral periosteum of the
ischium.
One randomized control trial of 14 patients compared artificial sphincter with a
program of supportive care (166). Supportive care included all aspects of
conservative management, such as physiotherapy, dietary advice,
pharmacotherapy, and advice regarding skin care, odor management, anxiety
reduction, and use of incontinence aids or appliances. Significant improvements
in continence scores and QoL measures were seen in the artificial sphincter group
but not in the control group at 6 months follow-up. Explantation rate was 14% (1
of 7 patients). Two other patients had complications, including severe fecal
impaction and perineal wound erosion requiring reoperation. The authors
conclude that the artificial sphincter is safe and effective compared with
supportive care alone. They anticipate perioperative and late complications,
which may require explantation in up to one-third of patients. It is remarkable that
only one patient (14%) whose condition was managed conservatively had
significant improvement based on continence scores, whereas the status of all
others was relatively unchanged.
1866FIGURE 31-7 Acticon Neosphincter. This device includes an inflatable cuff placed
around the anal canal, a balloon reservoir stored behind the pubic bone, and a pump
located in the labia.
Another study compared the effectiveness of artificial sphincter with dynamic
graciloplasty (167). Two surgeons each performed four consecutive operations
with each technique to minimize the learning curve of a new operation. Each
1867started with a different procedure to avoid discrepancies in the time of follow-up.
This prospective cohort study involved eight patients in each group who had
similar demographic variables. Length of follow-up was 44 months in the
artificial sphincter group and 39 months in the dynamic graciloplasty group. Early
postoperative complications were similar in each group at 50%, as were late
complications, with both groups reporting a high reoperation rate of 63%. There
were six (75%) late complications in the artificial sphincter group, of which three
(38%) were nonreversible and required explantation. Postoperative continence
scores were significantly lower with the artificial sphincter than with
graciloplasty. The authors conclude that artificial sphincter has better efficacy
and similar morbidity compared with dynamic graciloplasty. The rate of late
complications for the artificial sphincter exceeded that reported in the literature,
which may indicate poor long-term durability. Postoperative continence scores
reflect those reported for artificial sphincter but are far worse than those for
dynamic graciloplasty. The authors feel that the learning curve with the artificial
sphincter is less important than that with graciloplasty.
Artificial Magnetic Sphincter
The artificial magnetic sphincter (Magnetic Anal Sphincter; Fenix, Torax Medical
Inc., Shoreline, MN) is a small, flexible band of connected titanium beads with
magnetic cores. This encircles the EAS and creates a barrier. Pressure with
defecation causes the beads to separate and the stool to be evacuated.
Technique
Access to the EAS is achieved in the same fashion as a sphincteroplasty. A tunnel
is created circumferentially around the EAS taking care to avoid injuring the
pudendal nerve bundles. This is done with probing with a single digit around the
outside of the EAS. An introducer tool is placed around the anal canal in the
tunnel created and the sizing tool is connected. When the proper size has been
ascertained, the same introducer tool is used to introduce the implant by threading
the suture through the cross-hole feature. The implant is introduced in a linear
shape, then closed around the EAS to form an annular shape. The suture and
introducer tool are removed after the implant is in place.
Efficacy
The magnetic anal sphincter has been available since 2011 and is available in
Europe. The FDA approval in the United States is based on a multicenter,
prospective nonrandomized clinical study of 35 subjects, of which a majority had
sustained obstetrical injury, and were not candidates for or had previously failed
conservative treatment with less invasive therapy options. This study examined
1868the safety and probable benefit data at 6, 12, 24 and 36 months. Combining all
adverse events, 37% of patients experienced moderate to severe complication. At
36 months, 57% of patients reported a 50% or greater reduction in fecal
incontinence episodes and improvement in the FIQoL Score was seen in all
categories (168). In 2011 a prospective, nonrandomized study of 20 patients
demonstrated significant improvement in fecal incontinence severity and the
FIQoL Score, surgical time, and hospital stay were shorter for the magnetic
sphincter group compared to the artificial sphincter group (165).
Percutaneous Tibial Nerve Stimulation
Based on the same principle of neuromodulation as sacral nerve stimulation,
PTNS offers a more minimally invasive option.
Technique
The technique is identical to PTNS for urge urinary incontinence (Chapter 29,
page 725). The tibial nerve is stimulated percutaneously with a small needle 5-cm
cephalad to and 2-cm behind the medial malleolus. The needle is inserted and
advanced 2-cm deep, then connected to the lead wire, which is connected to the
stimulator. With this technique, the nerve is stimulated electrically for 30 minutes
once or twice per week for several consecutive weeks. An alternative is to use a
skin-surface electrode, referred to as “transcutaneous” stimulation.
Efficacy
The American Gastroenterology Association guidelines recommend sacral nerve
stimulation, however, they state that PTNS should not be used for managing fecal
incontinence until further evidence is available (118). The largest trial, published
in the Lancet (CONFIDeNT; 227 patients randomized to PTNS vs. control) did
not show a significant benefit of PTNS once per week for 12 weeks in their
primary outcome, as 38% in the PTNS group had a 50% or greater reduction in
the number of episodes of fecal incontinence per week compared to 31% in the
control group (OR 1.28, CI 0.72–2.28). However, PTNS did result in a significant
reduction in the mean number of total episodes of fecal incontinence per week
and mean number of episodes of urge fecal incontinence per week, compared with
control (a needle inserted to 2 mm but no electrical stimulation). Although
statistically significant, the clinical interpretation of a reduction from 6 episodes
of fecal incontinence per week to 3.5 episodes may or may not be interpreted as
helpful to patients (169).
THERAPEUTIC APPROACH TO CHRONIC CONSTIPATION
1869As with fecal incontinence, it is imperative to attempt conservative
management of constipation and defecatory dysfunction before pursuing
surgery. Initial evaluation should focus on identifying any underlying
systemic conditions (see Table 31-1) associated with disordered defecation and
optimizing treatment for these conditions. In the absence of systemic etiologies, it
is reasonable to proceed with empiric, nonsurgical management, such as diet,
fiber supplementation, and toileting behavior. Biofeedback and laxatives can be
used in more severe cases. Initially, disimpaction with regular enemas or laxatives
is essential if the patient has fecal impaction. Symptoms that persist despite a
trial of conservative management indicate the need for further evaluation of
colonic and anorectal function. A diagnostic and management algorithm for
idiopathic (nonsystemic) constipation is shown in Figure 31-8. Treatment should
be tailored to the underlying cause. Some conditions associated with disordered
defecation are best treated using nonsurgical techniques, whereas others may
benefit from surgery after conservative management has failed. As with fecal
incontinence, the lack of consistent outcome measures in the literature makes it
difficult to compare efficacy among treatments.
Nonsurgical Treatment
Nonsurgical management focuses on maximizing anorectal function through
alteration of stool characteristics or behavioral modification. Stool
consistency and volume can be manipulated by lifestyle, behavioral and
dietary means to achieve passage of one stool every day or every other day.
This is the mainstay of first-line treatment options for patients with normal
and slow-transit constipation. These modifications include an increase in
physical activity, toilet retraining, and dietary changes. Physical activity,
most beneficial in early morning, can lead to intestinal gas clearance, less
bloating and constipation. Toilet retraining includes instructions not to
ignore urges to defecate, use a “brace-pump” technique with the knees
higher than the hips and feet supported on a step to straighten the anorectal
angle. The patient is instructed to do deep-relaxation while defecating, avoid
straining when passing stool and not stay on the toilet for more than 5 to 10
minutes. Finally, drinking hot caffeinated beverages and eating breakfast
within an hour of waking up can take advantage of the gastrocolic reflex and
increase intestinal motility (98).
Abdominal massage produces a response in the rectum and anus by
stimulating the somatovisceral reflexes resulting in bowel peristalsis which
decreases colonic transit time and increases bowel movement frequency (173)
and has been shown to be acceptable and effective, especially with
neurogenic bowel (174,175).
18701871FIGURE 31-8 Diagnosis and management of chronic constipation. (From Hayat U,
Dugum M, Garg S. Chronic constipation: update on management. Cleveland Clinic
Journal of Medicine 2017;84(5):397–408.)
Physical therapy and biofeedback can be useful for coordinating pelvic floor
and anal sphincter relaxation with defecation.
Pharmacologic Approaches
Dietary Modification and Fiber
The role of increased fluid and fiber intake for the treatment of constipation
1872is controversial. For years, it has been a commonly accepted belief that
constipation is caused by low fluid intake and can be improved by increasing
consumption. Several studies showed no association between fluid intake and
constipation (3,176,177). However, one large study of 21,012 nursing home
residents found a weak association between decreased fluid intake and
constipation with an odds ratio of 1.49 (95% CI 1.21–1.82) (178). A review of
articles examining water intake and constipation in children and adolescents
found an association between decreased fluid intake and constipation, however,
an association between increased fluid intake for the successful treatment of
constipation could not be determined (179). Overall, the existing data do not
support increased fluid intake to treat constipation unless there is evidence of
dehydration (176,180).
The addition of fiber (25 to 30 grams daily) may improve constipation through
several mechanisms. Bulk-forming laxatives include insoluble fiber (wheat bran)
and soluble fiber (psyllium, methylcellulose, inulin, calcium polycarbophil). Fiber
acts as a stool-bulking agent and improves stool consistency through water
absorption. It can act as a substrate for bacterial proliferation and gas production.
These mechanisms of action are believed to result in increased colonic motility,
decreased transit time, and increased stool frequency.
Fiber therapy appears to have a beneficial effect in the treatment of
diverticular disease (181), constipation of pregnancy (19), and possibly IBS
(46). It is most effective for normal-transit constipation. Although psyllium fiber
of up to 30 mg/day in divided doses is recommended as a therapeutic option for
FC, dose-dependent bloating, distention and flatulence may affect tolerance to
this regimen. Increasing dietary fiber is less likely to benefit patients with slowtransit constipation or refractory outlet dysfunction (19,27,97). Up to 60% of
patients reported adverse effects with 1 month of insoluble fiber use (177). A
review of 7 RCTs (n = 254) in which older adults were assigned to either dietary
fiber or placebo showed no improvement in stool frequency in two trials looking
at psyllium fiber. Results from three trials of galactooligosaccharide were mixed
(the product is not readily available to consumers). The use of a mixture of fiber
(guar gum and wheat bran) and lactitol (osmotic agent) in yogurt resulted in
increased stool frequency in 51 medical and surgical inpatients. It is unclear
whether the fiber or the osmotic agent was responsible for this result (3). Dietary
fiber intake for patients with constipation was similar to that of controls in several
studies (182,183). A meta-analysis of 36 randomized trials using laxatives or fiber
therapy for the treatment of constipation showed that the use of fiber or laxatives
resulted in increased stool frequency and improved symptoms without the
presence of severe side effects (184). Conversely, another meta-analysis showed
an inability to restore transit time and stool weight in constipated patients using
1873dietary fiber (185). Approximately one-half of the patients in another study
responded to fiber treatment, but a much better response occurred in patients
without an identifiable structural or motility disorder (186). Consequently, a lowfiber diet may be a contributing factor in chronic constipation, and an empiric trial
of fiber therapy can be expected to help some patients. Side effects of increased
gas production may limit compliance with treatment, so doses should be slowly
titrated. Fiber therapy should be avoided in patients with impaction, megacolon or
megarectum, or obstructive gastrointestinal lesions. Fiber therapy should be used
with caution in patients with cognitive dysfunction (dementia), difficulty with
ambulation, and underlying neurogenic disease for fear of worsening the
condition. There is no evidence to substantiate the recommendation for extra
water intake with fiber supplements (187) unless the patient is dehydrated (173).
Laxatives
Laxatives are commonly used to treat constipation and disordered defecation
(Table 31-13). Many classes of laxatives are available over the counter.
Bulk-forming Laxatives
These come in a natural, soluble form (psyllium), and a synthetic form
(Metamucil, Konsyl, Citrucel), and are felt to be the safest laxatives. They have
mechanisms of action and side effects similar to that of fiber and may take several
days to have an effect (173).
Hyperosmolar Laxatives
These consist of poorly absorbed substances that bulk and soften the stool, while
stimulating and lubricating the gastrointestinal tract. This is done by increasing
intraluminal osmolarity and water absorption. Because it is not absorbed
systemically, this laxative has no drug interaction or contraindication, making it
safe for children and the elderly. Examples include nonabsorbable sugars
(lactulose and sorbitol), glycerin, and polyethylene glycol (GoLytely, MiraLAX).
Polyethylene glycol is a common preoperative bowel preparation. Side effects are
diarrhea, increased flatus, and abdominal cramping (188). A randomizedcontrolled trial of polyethylene glycol versus placebo in patients with irritablebowel syndrome, constipation type (IBD-C) did show improvements in stool
frequency consistency and straining. There was no difference in abdominal pain
or bloating over 4 weeks (189).
Emollient Laxatives
These agents are divided into two subsets: docusate salts and mineral oil. The
docusate salts have hydrophilic and hydrophobic properties similar to detergents.
They soften stool and decrease surface tension by increasing stool water and lipid
1874content. Examples include docusate calcium (Surfak), docusate potassium
(Dialose, Kasof), and docusate sodium (Colace, Comfolax). They improve the
absorption of other laxatives and are combined in preparations with stimulant
laxatives such as Correctol, Peri-Colace, and Feen-a-Mint. The limited
absorption of mineral oil allows it to penetrate and soften the stool. It can be used
orally or rectally. Prolonged daily use can lead to decreased absorption of the fatsoluble vitamins A, D, E, and K. Use of mineral oil should be avoided in elderly
and debilitated patients, and in those with esophageal motility disorders because
of the potential for aspiration pneumonia. Side effects include diarrhea, anal
leakage, and pruritis ani (188).
Saline Laxatives
These usually contain magnesium cations and phosphate anions that are relatively
nonabsorbable and produce an osmotic gradient with increased water absorption.
They stimulate intestinal motility by increasing cholecystokinin release. Fastacting effects can be seen with oral (2 to 6 hours) and rectal (15 minutes)
preparations. Examples include magnesium citrate, magnesium hydroxide (Milk
of Magnesia), magnesium sulfate, sodium phosphate, and biphosphate (Phosphosoda, Fleet enema). Although generally well tolerated, electrolyte abnormalities
can occur. These side effects should be avoided in patients with renal
insufficiency because of the potential for magnesium toxicity (188).
Stimulant Laxatives
These are found in three basic types: castor oil, anthraquinones, and
diphenylmethanes. A metabolite of castor oil, ricinoleic acid, increases intestinal
motility and secretion. Anthraquinones (cascara sagrada, senna [Senekot],
casanthranol [aloe], and danthron) are absorbed by the small intestine and
stimulate motility by increasing intraluminal fluid and electrolyte content.
Diphenylmethanes (phenolphthaleins [Feen-a-Mint, Correctol] and bisacodyl
[Dulcolax]) have a mechanism of action similar to anthraquinones. These agents
are potent and are intended for short-term use in cases refractory to bulk or
osmotic laxatives. They are rapid acting (under 12 hours). It has been a longstanding belief that prolonged use can lead to a dilated atonic colon known as
cathartic colon syndrome, melanosis coli, or neuronal degeneration. Over the past
decade the theory that stimulant laxatives damage the autonomic nervous system
when used at recommended doses has been refuted (176). Other side effects
include cramping, nausea, and abdominal pain (188).
Prokinetic Agents
Medications that stimulate gastrointestinal motility primarily through
1875neuromodulation of acetocholine levels include metoclopramide, cholinergic
agonists (bethanechol), cholinesterase inhibitors (neostigmine), and serotonin
agonists. Their efficacy in the treatment of chronic idiopathic constipation is
uncertain. Metoclopramide is better for upper gastrointestinal motility disorders
(188). Selective serotonin 5HT4-receptor agonists (prucalopride, naronapride,
velusetrag) stimulate serotonin receptors in the intestinal walls to increase
muscular contraction of the colon (173). Adverse effects reported include
headache, nausea, abdominal pain and cramps. Two 5-HT4 receptor agonists were
withdrawn from the market (cisapride, tegaserod) because of serious
cardiovascular adverse events resulting from their affinity for hERG-K+ cardiac
channels, a property not found in the newer 5-HT4 agonists (97).
Intestinal Secretagogues
Chloride channel activators (lubiprostone) increase intestinal fluid secretion and
gut motility. A prostaglandin E1 derivative, this drug is licensed for the treatment
of chronic idiopathic constipation and should only be prescribed by experienced
clinicians. Adverse effects include nausea and headache (190). Guanylate cyclaseC receptor agonist (linaclotide, plecanatide) increases intestinal fluid secretion
and transit and is licensed for the treatment of moderate-to-severe IBS associated
with constipation as it decreases visceral pain (173).
Opioid-induced constipation (OIC) is a distinct diagnosis within the Rome IV
framework with specific diagnostic criteria (46). Initial treatment is the same as
for those patients with FC. Laxatives are recommended for the prophylaxis and
management of OIC. Additional medications include opioid receptor antagonists.
If the antagonist acts centrally, this may precipitate opioid withdrawal symptoms
(naloxone, nalbuphine). Medications that act peripherally only block the opioid
receptors in the gastrointestinal system and will not lead to withdrawal symptoms
(subcutaneous methylnaltrexone, alvimopan, naloxegol, naldemedine), which
may be an important method of providing constipation relief to palliative,
oncology, and substance use disorder populations.
Behavioral Approaches
Behavioral techniques such as biofeedback and bowel regimens may have a role
in certain conditions associated with constipation and defecatory dysfunction.
Overall, these approaches have far less application to disordered defecation than
to fecal incontinence. Biofeedback is important in the treatment of
dyssynergic defecation. Relaxation techniques and behavioral modification
may be helpful for IBS. Bowel regimens in conjunction with laxatives,
suppositories, and enemas can facilitate emptying by optimizing the gastrocolic
1876reflex and increased peristaltic activity.
Efficacy of Nonsurgical Treatment
Irritable Bowel Syndrome
The most commonly used first-line treatment for the constipation variant of
IBS is fiber supplementation and osmotic laxatives. The efficacy of bulking
agents for this condition is controversial, and many studies, including metaanalyses, exhibit an effect similar to placebo. There may be benefit to the use of
fiber because of the high placebo effect with IBS treatment and lack of serious
adverse events associated with its use. However, patients may experience
exacerbation of bloating and abdominal discomfort with fiber therapy.
Randomized trials and meta-analysis revealed a beneficial effect of polyethylene
glycol (MiraLAX) over placebo for the treatment of chronic constipation
(191,192). They can be useful as adjunctive treatment options, but can exacerbate
abdominal pain and discomfort.
Colonic Inertia and Slow-Transit Constipation
Patients with slow-transit constipation tend to respond poorly to fiber
supplementation, although most have already tried an empiric trial of fiber
before testing to confirm the diagnosis (186). Some patients may benefit from
regular toileting, either in the morning or after meals when there is increased
colonic motor activity. Biofeedback may have modest short-term benefits, but the
long-term effect is questionable (193). A randomized-controlled trial of eight
biofeedback sessions over a 4-week period conducted in 30 cognitively intact
older people reported an increase in stool frequency from 2 to 4 bowel
movements per week compared to controls who received counseling (194).
Enemas and suppositories can be used in conjunction with bowel regimens. It is
reasonable to attempt a trial of any of the laxatives listed in Table 31-13.
Stimulant laxatives commonly are used, but questions remain about the
development of neuronal degeneration with prolonged usage and the need for
increasing doses to yield the same desired effect. It is imperative that patients
adhere to and not exceed the recommended dosages. Osmotic agents are likely the
safest and most effective. Increasing amounts of data regarding newer prokinetic
agents may demonstrate that this class of medication is the ideal choice when the
goal is to stimulate colonic motility.
Dyssynergic Defecation
As with slow-transit constipation, initial management using bowel regimens,
laxatives, enemas, suppositories, and fiber supplementation is appropriate
for patients with dyssynergic defecation, yet many will have already tried
1877conservative management before undergoing testing to confirm the
diagnosis. These treatments are relatively well tolerated with few serious side
effects. They have not been shown to have greater efficacy when compared with
placebo, and their role in the treatment of dyssynergic defecation remains
uncertain. Specific treatment for this condition tends to focus on biofeedback
because of studies indicating that this is an acquired behavioral disorder of
defecation. Modalities such as diaphragmatic muscle training, simulated
defecation, and manometric or EMG-guided anal sphincter and pelvic muscle
relaxation have been employed independently or combined with other techniques.
These techniques have yielded symptomatic improvement in approximately 60%
to 80% of patients. Many patients with dyssynergic defecation have abnormal
rectal sensation, so rectal sensory conditioning may provide additional benefits
(37,195). Others have tried botulinum toxin injections to paralyze the puborectalis
and anal sphincter muscle. Small case series, with and without ultrasound
guidance have shown modest early improvement but the results do not appear to
be long lasting (196–198). A more recent randomized trial of 48 subjects
comparing botulinum toxin to biofeedback retraining found better initial
improvement with the botulinum toxin (70% vs. 50%) but no difference at 1 year
(33% vs. 25%) (199). Thus, reapplication is necessary. Biofeedback and pelvic
floor therapy should be first-line treatment, and in cases that are refractory,
botulinum toxin injection into the puborectalis muscle can be considered (200).
Pessary for Treatment of Pelvic Organ Prolapse
Pessaries of various shapes and sizes have been used for centuries to treat
pelvic organ prolapse (201). They are a safe alternative to surgery, with the
most common complications being increased vaginal discharge and erosion
or ulceration of the vaginal wall. Although pessaries represent a common
therapeutic modality, there are limited data regarding fitting and management
(202). Even less is known about which type of pessary is better for enteroceles
and rectoceles, although the site of prolapse does not appear to affect the ability to
retain a pessary (203). Pessaries can be divided into subtypes of supportive and
space occupying (204). Some of the space-occupying pessaries, such as the
Gellhorn and cube, use a suction mechanism to maintain vaginal retention,
whereas others, like the donut, do not. In theory, space-occupying pessaries and
those that exert forces against the posterior wall and vaginal apex (donut, inverted
Gehrung) should aid in treatment of rectoceles and enteroceles. However, there is
a lack of data regarding the efficacy of pessaries for relieving symptoms of
disordered defecation. One prospective study found that stage III to IV posterior
vaginal wall prolapse was an independent predictor for discontinuation of pessary
use in favor of surgical repair (205). The only randomized crossover trial
1878comparing different types of pessaries (ring and Gellhorn) found improvement in
QoL measures that did not differ according to pessary type. Protrusion and
voiding dysfunction symptoms were most improved (206). In a secondary
analysis of women enrolled in a study that sought to evaluate if pessary use is
associated with improvement of bulge symptoms from prolapse and perception of
body image, 43 out of the original 104 woman completed validated questionnaires
on bowel symptom severity and effect on QoL at baseline and again after 12
months of continuous pessary use (207). There is marked improvement in
symptom severity and QoL by using a pessary. This suggests a potential role for
nonsurgical management of pelvic organ prolapse to help provide relief of bowel
symptoms. More research is needed to determine the role of pessaries for
treatment of rectoceles, enteroceles and symptoms that are likely to be improved
using a pessary.
1879THERAPEUTIC APPROACH TO ACUTE CONSTIPATION
Patients may present with severe abdominal pain postoperatively. Anesthetic
effects, pain, and medications such as opioids, oral iron, NSAIDs, ondansetron,
and gabapentin, for example, are known to have constipating effects (Table 31-
2). The laxative therapies mentioned above have been tested in the chronic
constipation population but not for this relatively common postoperative scenario.
There is sparse literature examining prevention or treatment options for
constipation postoperatively and evidence-based recommendations cannot be put
forward (208–210). A randomized, double-blind, placebo-controlled trial of
postoperative pelvic reconstructive surgery patients showed that women receiving
senna (8.6 mg) with docusate (50 mg) had a shorter time to first bowel movement
(3 vs. 4 days) and the placebo group needed a stronger agent (magnesium citrate)
to initiate a bowel movement more often as compared to the treatment group
(44% vs. 7%, P <0.01) (211). From the colorectal literature, a retrospective
review of 183 patient charts concluded that early ambulation and routine
polyethylene glycol each contribute to significantly shorter times to first bowel
movement than those with routine care (212). From the urogynecology literature,
a randomized controlled trial of 131 patients receiving polyethylene glycol with
docusate sodium postoperatively compared to docusate sodium alone showed no
difference in time to first bowel movement (213). It should be noted, however,
that 42% of women in the placebo group took additional laxatives compared to
only 23% in the PEG arm (P = 0.02). Opioid-induced constipation and ileus is
better studied and a systematic review of the literature suggests that peripherally
acting μ-opioid receptor antagonists may be effective in treating opioid-induced
bowel dysfunction and postoperative ileus (214). After other causes of acute
abdominal pain have been ruled out, constipation can be confirmed by flat-plate
plain film x-ray. Once diagnosed, the following regimen of three medications can
be used: (1) Magnesium citrate 300 mL po × 1; (2) Bisacodyl 30 mg po × 1; (3)
Sodium Phosphate enema PR × 1.
This recommendation uses three agents with three different mechanisms
of action. Other options include magnesium hydroxide 400 mg/5 mL 30 mL
po TID or mineral oil 15 mL po TID. Each regimen can be titrated to the
patient’s needs; for example, the sodium phosphate enema may be too
powerful and a tap water enema or glycerin suppository will suffice.
In the older adult susceptible to electrolyte derangements and renal
dysfunction, sodium phosphate and magnesium-based products should be
used with caution (215). Other options include magnesium hydroxide 400
mg/5 mL 30 mL po TID or mineral oil 15 mL po TID. Ideally, if an
1880iatrogenic cause is identified, this will be discontinued. If, however,
constipating agents must be continued, using osmotic laxatives concomitantly
should prevent constipation. For example, PEG 3350 17 g in 1 cup
water/juice daily until soft BM, then as needed, may be recommended.
Adjunctive Therapies
Acupuncture, peppermint oil and probiotics are modalities that may help
improve chronic constipation. A randomized trial of acupuncture for chronic
severe FC in over 1,000 patients showed significant improvement over 8
weeks of treatment and 20 weeks of follow-up compared to the control group
with about one-third of the treatment arm having three or more complete
spontaneous bowel movements per week, compared to only 14% in the
control arm (P <0.001) (216). Peppermint oil has not been studied for
constipation alone; however, in the IBS literature it has been reported to be
safe and modestly effective in the short-term for global IBS symptoms (217).
The most commonly reported adverse event is heartburn. A systematic
review and meta-analysis of the efficacy of pro/pre/synbiotics in IBS and
chronic constipation concludes that probiotics are effective for IBS
symptoms, although the most beneficial species and strains are not yet
known. Evidence for prebiotics and synbiotics are unclear, as are the efficacy
of all three on chronic constipation (218).
Surgical Treatment
Following is a review of the efficacy of various surgical treatments for specific
conditions associated with constipation and disordered defecation.
Slow-Transit/Colonic Inertia
Subtotal colectomy with ileosigmoid or ileorectal anastomosis is considered
by many to be the surgical treatment of choice for slow-transit constipation
refractory to medical management. Most surgeons restrict the use of this
surgical procedure to the most extreme cases and typically operate on fewer than
10% of patients. Strict criteria for surgery include the following: chronic, severe,
disabling symptoms unresponsive to medical therapy; slow transit in the proximal
colon; no evidence of pseudo-obstruction; and normal anorectal function (188).
Success rates are variable and depend on several factors. An extensive review of
colectomy for slow-transit constipation analyzed 32 studies from 1981 to 1988
and found satisfaction rates ranged from 39% to 100% (219). Higher success rates
occurred in studies in the United States (n = 11, median 94%, range 75% to
100%) and prospective studies (n = 16, median 90%, range 50% to 100%).
1881Superior outcomes occurred in those who had a complete physiologic evaluation
and proven slow-transit constipation. Patients with anismus had higher rates of
recurrent symptoms and lower satisfaction levels (220). Poorer outcomes
occurred with ileosigmoid and cecorectal anastomosis than with ileorectal
anastomosis. Those with segmental resection (hemicolectomy) had the worst
outcome. None of the studies had a comparison group, and outcomes were
variable and lacking validated measures. Morbidity associated with the operation
included small bowel obstruction (median 18%, range 2% to 71%), need for
reoperation (median 14%, range 0% to 50%), diarrhea (median 14%, range 0% to
46%), fecal incontinence (median 14%, range 0% to 52%), recurrent constipation
(median 9%, range 0% to 33%), persistent abdominal pain (median 41%, range
0% to 90%), and permanent ileostomy (median 5%, range 0% to 28%). Mortality
ranged from 0% to 6% (184). A QoL study revealed that the score correlated
poorly with frequency of bowel movements. However, a lower score was seen in
those patients who had persistent abdominal pain, diarrhea, fecal incontinence,
and permanent ileostomies. Overall satisfaction with the procedure was very high
and correlated with the QoL score (221,222). Surgical alternatives to subtotal
colectomy include ileostomy, cecostomy with antegrade continence enemas,
and sacral nerve stimulation. Subtotal colectomy has never been directly
compared with ileostomy, but those who had a permanent diversion after subtotal
colectomy had lower QoL scores. Patients undergoing cecostomy with antegrade
continence enemas can expect to have satisfactory function approximately onehalf of the time, with most requiring additional revision procedures secondary to
stomal complications (223). Although sacral nerve stimulation has primarily been
used for fecal incontinence, the results of a few small studies evoked optimism for
its use in chronic constipation and slow-transit constipation (224–226). The
Cochrane review of sacral nerve stimulation for fecal incontinence and
constipation cannot support its use for constipation as the two trials included did
not improve symptoms in patients with constipation (126).
Pelvic Organ Prolapse
Women with defecatory dysfunction or fecal incontinence may have a
concomitant posterior vaginal wall prolapse (rectocele). The variety of
surgical treatment techniques for the repair of rectocele include posterior
colporrhaphy, defect-directed repair, transanal repair, and abdominal repair
with sacral colpopexy. When an enterocele is present, a culdoplasty usually is
performed. In cases of perineal descent, abdominal sacral colpoperineopexy is the
procedure of choice. Suture rectopexy can be performed in conjunction with
sacral colpoperineopexy if rectal prolapse is present. Despite the routine use of
these procedures, data are limited regarding symptomatic improvement of
1882disordered defecation. Rectocele repair is indicated for bothersome prolapse
bulge symptoms and not to be done with the intent of correcting disordered
defecation. A systematic review and practice recommendation out of the United
Kingdom confirms that the use of rectovaginal reinforcement procedures for the
purpose of improving constipation symptoms is not supported by the literature
(227). Greater detail regarding the specific techniques for many of these
procedures will be provided in Chapter 30. This section will focus on surgical
outcomes, including anatomic cure of prolapse, improvement of defecatory
dysfunction symptoms, and morbidity associated with the procedure.
Posterior Colporrhaphy
Posterior colporrhaphy has been the surgical procedure for rectocele repair
preferred by gynecologic surgeons for more than 100 years. Traditional
posterior colporrhaphy narrows the vaginal caliber through plication of the
rectovaginal septum and usually includes a perineorrhaphy, which narrows
the introitus. Despite its broad use, there is a paucity of data regarding long-term
anatomic success, symptomatic improvement, and sexual function following the
procedure. The outcomes of several studies are summarized in Table 31-15 (228–
247). Anatomic cure and relief of vaginal bulge occurred in 76% to 96% of
patients. In these studies, the procedure was ineffective at treating constipation,
vaginal digitations (splinting), and fecal incontinence. Dyspareunia developed in
7% to 26% of patients with and without levator plication (228–232,248). As early
as 1961, high rates of dyspareunia have been reported with this procedure in as
many as 50% of patients (249).
The successful anatomic support obtained with this procedure is offset by the
modest relief of functional symptoms and high rate of de novo dyspareunia.
However, a prospective case series of 38 women undergoing posterior
colporrhaphy along with concomitant procedures for rectocele and obstructed
defecation revealed markedly different results (250). Fascial plication was
performed without levator plication, and perineal body reconstruction rather than
routine perineorrhaphy was employed when indicated. Anatomic cure rate was
87% at 12 months and 79% at 24 months. Subjective cure rate was 97% at 12
months and 89% at 24 months. There was significant improvement in
preoperative and postoperative symptoms for constipation (76% vs. 24%),
digitations (100% vs. 16%), awareness of prolapse (100% vs. 5%), obstructed
defecation (100% vs. 13%), and dyspareunia (37% vs. 5%). There was no
difference in fecal incontinence and only one case of de novo dyspareunia. The
authors attribute their improved anatomic and functional outcomes and combined
improvement in dyspareunia to exclusion of levator plication, perineorrhaphy,
and excision of vaginal epithelium. An additional benefit may be derived during
1883mobilization of the vaginal epithelium, when scar tissue from prior episiotomy or
surgery is divided. They found that preoperative defecating proctography was of
limited value and have stopped its routine use as part of the preoperative
evaluation for women with symptomatic rectoceles and obstructive defecation.
This group has developed a classification system of the perineum that can help
surgeons decipher when to use a perineorrhaphy and when to exercise less
aggressive perineal reconstructive techniques (251).
Table 31-15 Rectocele Repairs
1884Defect-Directed Repair
1885The goal of a defect-directed repair or site-specific repair is to restore normal
anatomy (38). This procedure can be combined with a perineal body
reconstruction, if necessary, but usually does not routinely involve
perineorrhaphy. Table 31-15 lists the anatomic and functional outcomes for this
type of repair. Anatomic cure rates range from 82% to 100%, which are
similar to those for posterior colporrhaphy. This procedure resulted in
modest improvement for symptoms of difficult evacuation, vaginal bulge,
and vaginal digitations (234–238,248). Constipation symptoms significantly
decreased in only one study (233,234). All studies reported low rates of de novo
dyspareunia with good functional and anatomic outcomes, but the long-term
durability of the procedure is unknown. All but one of these studies included
concomitant prolapse and urinary incontinence procedures.
A randomized clinical trial of 106 women with stage II or greater posterior
vaginal wall prolapse compared posterior colporrhaphy, defect-directed rectocele
repair, and defect-directed repair augmented with a porcine small intestinal
submucosal (252). Subjects completed validated pelvic floor instruments at
baseline and 6 months, 1 year, and 2 years after surgery. Anatomic failure was
defined as pelvic organ prolapse quantitation system (POPQ) point Bp > or = –2
at 1 year. There was a significant improvement in prolapse and colorectal scales
in all groups with no differences between groups. The proportion of subjects with
functional failures was 15% overall, and not significantly different between
groups. Posterior colporraphy and defect-directed repairs resulted in similar
anatomic and functional outcomes, although the addition of a porcinederived graft did not improve anatomic outcomes. On average, all bowel
symptoms evaluated were significantly improved 1 year after surgery, with no
differences between treatment groups. The development of new “bothersome”
bowel symptoms after surgery was uncommon (11%). After controlling for age,
treatment group, comorbidities, and preoperative bowel symptoms, corrected
postoperative vaginal support (stage 0/I) was associated with a reduced risk of
postoperative straining (adj. OR 0.17 95% CI 0.03–0.9) and feeling of incomplete
emptying (adj. OR 0.1 95% CI 0.01–0.52). This led the authors to conclude
that resolution or improvement in bowel symptoms can be expected in the
majority of women after rectocele repair (253). A similar study conducted in
2012 concluded that the underlying cause of the defecatory symptoms will likely
dictate whether or not a woman finds improvement after rectocele repair and that
women should be counseled that their defecatory symptoms and bowel habits
may or may not improve after rectocele repair (233).
Transanal Repair
Transanal repair involves repair of the rectocele through a transanal incision
1886with excision of redundant rectal mucosa and plication of the rectovaginal
septum and rectal wall. The procedure was developed and is primarily used
by colorectal surgeons to treat constipation or obstructed defecation
associated with “low” or distal rectoceles. The advantages of this approach
include excision of redundant rectal mucosa and the ability to treat other
anorectal pathologies, such as hemorrhoids or anterior rectal wall prolapse
(254). Disadvantages include the inability to repair higher rectoceles, enteroceles,
cystoceles, uterine prolapse, and defects in the perineal body or anal sphincter
(255). Major complications of infection (6%) and rectovaginal fistula (3%) are
relatively common compared to transvaginal repairs (202). Most studies did not
require vaginal bulging or protrusion symptoms as a prerequisite for surgery. The
results of several studies are summarized in Table 31-15. The anatomic cure rate
was 70% to 98%, and symptoms of constipation, difficult evacuation, and vaginal
digitations appeared to improve (243–248).
Reviews to compare transanal with transvaginal rectocele repair use the results
of two small, randomized control trials (256–259). Women with compromised
sphincter function and other symptomatic prolapse were excluded. The results
for transvaginal repair were superior to those for transanal repair with
respect to subjective failure rate (relative risk [RR] 0.36, 95% CI 0.13 –1) and
objective failure rate (RR 0.24, 95% CI 0.09–0.64) (256). In one study, a
significant decrease occurred in the depth of rectocele on postoperative
defecography for the transvaginal group compared with the transanal group (2.73
cm vs. 4.13 cm, respectively) although the depth of rectocele on imaging does not
correlate with symptoms (259). The transvaginal group had fewer problems with
bowel evacuation, but this finding was not statistically significant. In one study,
researchers discovered that 38% of patients developed fecal incontinence
following transanal repair (228). In the two randomized trials, no significant
differences were seen in the rate of fecal incontinence or dyspareunia, but the
studies were underpowered to detect a difference (258,259). Although a vaginal
approach has been considered superior to a transanal approach for rectocele
repair, studies are retrospective and impossible to compare because the
indications for transanal repairs are generally different from those for
transvaginal repairs.
Posterior Fascial Reinforcement
Rectocele repair with graft augmentation became commonplace in the early
to late 2000s despite a paucity of supporting evidence indicating its benefits
over standard procedures. The reason for its emergence was the theory that
vaginal hernia repairs behave similarly to abdominal hernia repairs, which have a
documented decrease in recurrence when augmented with grafts. A variety of
1887graft materials have been employed with posterior colporrhaphy and defectdirected repairs including autograft, allograft, xenograft, and synthetic mesh.
Polypropylene type I monofilament, macroporous synthetic mesh is associated
with lower complication rates compared with other nonabsorbable synthetic
materials (260). The purpose of the graft is debatable. It can either be intended to
replace existing fascia as a permanent barrier or to provide an absorbable scaffold
for collagen deposition, scar formation, and remodeling. The ideal material should
have a low erosion rate, be relatively inexpensive, and decrease recurrence rates
without causing bowel or sexual dysfunction. Experience has demonstrated that
although reinforcement with graft augmentation may result in better anatomic
outcomes, there is no difference in subjective success at the cost of higher
complications such as mesh erosion and extrusion (261,262). Improvements in
objective outcomes are limited to the anterior vaginal wall and do not extend to
multicompartment or posterior vaginal wall mesh (261), thus confirming no role
for synthetic mesh augmentation for posterior repair. There is no evidence to
suggest that the addition of a graft to the posterior compartment improves
outcomes (252,261–263).
Abdominal Rectocele Repair
The abdominal approach to rectocele repair may be of value when a superior
defect in the rectovaginal fascia occurs in a patient with accompanying
enterocele, uterine prolapse, or vault prolapse. If a patient is undergoing an
abdominal or laparoscopic procedure such as a sacral colpopexy, the graft can be
extended along the posterior vaginal wall to correct proximal defects in the
rectovaginal septum (264). There are limited data regarding the efficacy of
abdominal rectocele repair. The indication for this procedure, and the need for
additional vaginal repair of distal defects, often is determined intraoperatively. An
ancillary study from the Pelvic Floor Disorders Network evaluating bowel
symptoms 1 year after sacrocolpopexy found that the majority of bothersome
bowel symptoms resolve after this procedure. There was no difference in
postoperative bowel symptoms among those who underwent a concomitant
rectocele repair and those who did not. The study was not developed to evaluate
the impact of concomitant rectocele repair on bowel symptom resolution and
those who underwent a rectocele repair had more severe baseline bowel
symptoms including worse obstructive symptoms (265).
Sacral Colpoperineopexy for Perineal Descent
Sacral colpoperineopexy is a modification of sacral colpopexy aimed at
correction of apical prolapse combined with rectocele and perineal descent
(39). A continuous graft is placed from the anterior longitudinal ligament of the
1888sacrum down to the perineal body. This procedure can be accomplished either
through a total abdominal approach or a combined abdominal and vaginal
procedure. If performing a total abdominal approach, the rectovaginal space
is opened, and the rectum is dissected off the posterior vaginal wall and
rectovaginal septum toward the perineal body. The graft is sutured to the
perineal body or as close to it as possible. A rectovaginal examination with the
surgeon’s nondominant hand facilitates this attachment by supporting the perineal
body. The graft is secured to additional points along the posterior vaginal wall
and apex, and sacral colpopexy is completed in the usual fashion.
If performing a combined abdominal and vaginal approach, the graft is
secured to the perineal body vaginally. The posterior vaginal wall is opened,
and a defect-directed rectocele repair is performed. Sacral colpopexy is
accomplished in the usual fashion except that the vaginal dissection is opened
superiorly, creating a window to the abdominal dissection. The graft can be
passed down from the abdominal field to the vaginal field and anchored inferiorly
to the perineal body and laterally to the arcus tendineus fascia rectovaginalis (Fig.
31-9).
Short-term outcomes for 19 patients who underwent sacral colpoperineopexy
indicated good anatomic results for apical and posterior support and for perineal
descent (39). Complete cessation of defecatory dysfunction symptoms was
accomplished in 66% of patients. In a report of outcomes for a slightly different
variation of the sacral colpoperineopexy, the authors’ technique involved
attachment of Marlex mesh to the perineal body using a needle carrier (266). The
failure rate was 25% and mesh erosion rate was 5% for 205 patients with up to
10-year follow-up. A study of Mersilene mesh erosion rates related to sacral
colpopexy and sacral colpoperineopexy noted similar erosion rates between sacral
colpopexy and colpoperineopexy when the vagina was not opened, 3.2% versus
4.5%, respectively (267). However, the erosion rate was 16% with vaginal suture
placement and 40% when the mesh was placed vaginally. The use of nonsynthetic
grafts such as dermal allograft and xenograft may help prevent high erosion rates.
In a case series of 11 patients, researchers performed sigmoid resection (if
indicated) and suture rectopexy in conjunction with sacral colpoperineopexy
using Alloderm for women with coexistent rectal prolapse, perineal descent, and
defecatory dysfunction. Early follow-up (12.5 ± 7.7 months) revealed excellent
improvement of defecatory dysfunction symptoms and QoL considerations, with
an 82% cure of perineal descent (268). A retrospective cohort of 38 women
revealed high satisfaction following abdominal sacral colpoperineopexy despite
the persistence of obstructed defecation symptoms 5 years after surgery
(269,270). Sacral colpoperineopexy may have value for a select group of
patients, but larger prospective series with long-term anatomic and symptomatic
1889outcomes are necessary to evaluate the durability of this procedure.
Rectal Prolapse
Rectal prolapse is an uncommon pelvic floor disorder with an incidence below
1% of the adult population; however, risk factors are similar between rectal
prolapse and pelvic organ prolapse. Although considered a benign condition,
symptoms can significantly negatively impact QoL. These include pain, bleeding,
seepage, defecatory dysfunction, fecal incontinence, and mass symptoms. The
prolapse may be occult (internal intussusception-producing symptoms but no
visible protrusion), partial (mucosal prolapse only) or full thickness (all layers of
the rectum come through the anus as concentric rings). Prolapsed internal
hemorrhoids are sometimes confused with rectal prolapse but are treated
differently.
Although medical management may ease symptoms of rectal prolapse, a
surgical consultation is usually warranted. Surgical management is usually
reserved for full-thickness complete rectal prolapse. A number of surgical
procedures are described for the treatment of rectal prolapse and are broadly
categorized into perineal or abdominal approaches. The most commonly utilized
perineal approaches are the Delorme procedure, which includes resection of
redundant rectal mucosa and plication of redundant rectal mucosa, and the
Altemeier (perineal rectosigmoidectomy) procedure that includes perineal
resection of full-thickness rectum. These perineal approaches offer easier
recuperation for patients, but have been considered to be less definitive in terms
of preventing recurrent rectal prolapse. The abdominal approaches have been
considered to be more durable, but with a higher incidence of surgical
complications and more difficult recovery. This belief and practice that abdominal
approaches have significantly lower recurrence rates has come from observational
studies, but several randomized controlled trials, two Cochrane reviews, and a
third systematic review have not been able to demonstrate this distinction (271).
A true benefit/risk comparison of perineal and abdominal approaches is
complicated by the significant variations in abdominal approaches, with major
variations in; whether the retrorectal space is dissected, whether mesh is utilized,
and whether a concurrent sigmoid resection is performed. Laparoscopic and
robotic variations of these approaches have been described in an attempt to
minimize the recovery time.
1890FIGURE 31-9 Abdominal sacral colpoperineopexy with sigmoid resection and suture
rectopexy. This sagittal view shows the posterior graft sutured to the rectovaginal fascia
and perineal body after defect-directed rectocele repair. The anterior graft is sutured to the
pubocervical fascia. Both sheets will be secured to the sacral periosteum to the right of the
rectum. Rectopexy sutures (left) have not yet been tied and secured. (Courtesy of Geoffrey
W. Cundiff, MD.)
Perineal Procedures
Perineal procedures are more easily tolerated because they avoid
laparotomy. They are ideal for patients at high-risk for perioperative and
postoperative morbidity and mortality. There are basically two perineal
procedures: the Delorme procedure and perineal rectosigmoidectomy (Altemeier
1891operation). Perianal encirclement procedures such as the Thiersch procedure are
no longer used because of poor success rates, high recurrence rates, and fecal
impaction.
The Delorme procedure was first described in 1900 and involves separation of
the rectal mucosa from the sphincter and muscularis propria, followed by
resection of the rectal mucosa, and plication of the distal rectal wall (muscularis
propria) (272) (Fig. 31-10). Recurrence rates range from 10% to 15% (273–276)
and there is a low morbidity of 4% to 12%, which includes infection, urinary
retention, bleeding, and fecal impaction. The recurrence rates were originally
thought to be up to 38% (277), but new evidence indicates the range may be
acceptable to patients who are eligible for abdominal surgery. There is a general
improvement in fecal incontinence and constipation. Fecal incontinence, chronic
diarrhea, and severe perineal descent are associated with failure of this procedure
(278). The Delorme operation may be preferred in cases where the prolapsing
segment is shorter than 3 to 4 cm or there is no circumferential full-thickness
prolapse, making perineal rectosigmoidectomy difficult to perform (277,279).
Perineal rectosigmoidectomy (Altemeier operation) involves a transanal
full-thickness resection of the prolapsed rectum and a coloanal anastomosis (280).
Recurrence rates are described up to 30% but the only two randomized controlled
trials comparing the Altemeier approach to an abdominal approach showed no
statistically significant difference in recurrence rates, although the studies were
not powered to show this (271). Patients generally have minimal pain and a
relatively uneventful postoperative course. Recurrent prolapse probably reflects
inadequate resection. Incontinence results are modest but seem to improve
substantially with the addition of levatorplasty. The addition of levatorplasty
appears to decrease the short-term recurrence rate (281), but there is no significant
change in constipation with this procedure. Most agree that perineal
rectosigmoidectomy with levatorplasty is the best procedure for very elderly
patients and those with profound comorbidity. This is the preferred approach for
patients with incarcerated, strangulated, or even gangrenous prolapsed rectal
segments who are not candidates for abdominal rectopexy.
1892FIGURE 31-10 Delorme procedure. After mucosal stripping to the full extent of the
prolapse, the circular smooth muscle or the rectum is plicated. A mucosa-to-mucosa
anastomosis is then performed.
Abdominal Procedures
Abdominal procedures vary with respect to the extent of rectal mobilization,
method of rectal fixation, and inclusion or exclusion of bowel resection.
The posterior approach is the most established and studied abdominal
procedure. It begins with dissection of the retrorectal space to and beyond
Waldeyer fascia. This dissection optimizes support by promoting fibrosis of the
rectum to the sacrum, and includes the division of the lateral ligament stalks with
a theoretical potential to cause an increased postoperative constipation as a result
of rectal denervation. This association is supported by a Cochrane review of 15
randomized controlled trials (282). This may be balanced by a lower recurrence
rate and may make this an attractive option for patients with fecal incontinence.
The alternative to the posterior approach is the ventral rectopexy.
The posterior procedures include some method for anchoring the posterior
rectum to the anterior sacrum. If performing a suture rectopexy, the fascia propria
of the rectum is secured with sutures to the sacral periosteum from S1–S3 (283).
The alternative is one of the mesh rectopexies, posterior mesh rectopexy (Wells
procedure), anterior mesh rectopexy (Ripstein, modified Ripstein), and
ventral mesh rectopexy (271,284,285). A variety of materials have been used for
these procedures, including absorbable, autologous, and permanent mesh. The
assumption is that the intervening material will provide increased support through
increased fibrosis. The posterior mesh rectopexy has the mesh secured to the
1893sacrum between the posterior rectum and the sacral promontory.
The ventral mesh rectopexy offers an alternative approach to the posterior
approach. The ventral mesh rectopexy incorporates an anteriorly placed mesh
support for fixation of the rectum to the sacral hollow. Rather than entering the
retrorectal space, the rectovaginal septum is dissected to expose the proximal twothirds of the rectovaginal septum (Denovillier fascia). A synthetic or biologic
mesh buttress is sutured to the anterior wall of the rectum at the point of its
intussusception and suspended to the sacral promontory. The available studies
show acceptable short- and long-term complication rates (271). There is
insufficient evidence to argue that posterior rectal prolapse repairs are better
or worse than anterior rectal prolapse repairs such as ventral mesh
rectopexy (271).
Aside from the dissection, and method of attachment, another surgical variation
is performing a concurrent sigmoid resection with the rectopexy (Frykman–
Goldberg resection rectopexy). The bowel resection is performed after
mobilization and before suturing (286). The theoretical advantages of a
rectosigmoid resection are: removal of abundant rectosigmoid, avoiding torsion or
volvulus; additional fixation through straightening of the left colon and decreased
mobility from the phrenocolic ligament; and creation of a dense area of fibrosis
between the anastomotic suture line and the sacrum. It is typically reserved for
patients with a long redundant sigmoid colon, although specific criteria have not
been proposed. Mesh rectopexies are usually avoided at the time of a bowel
resection because of concern for the increased complications and infections
associated with placement of a foreign body near a new wound on the bowel.
Finally, minimally invasive approaches to abdominal rectopexies have been
advocated as a means to decrease the recovery time. The laparoscopic approach
has similar safety and efficacy to the open techniques, and the effect on
continence and constipation tended to mirror the type of rectopexy performed. In
a small, randomized trial, there were significant short-term benefits with
laparoscopic rectopexy compared with open rectopexy, including earlier
ambulation, more rapid return to normal diet, shorter hospital stay, and
lower morbidity (287). Several studies have confirmed that recurrence rates are
equivalent (4% to 8%) as are complication rates (10% to 33%) (271). Robotic
surgery seems to be comparable to laparoscopic approaches.
Although there is a consensus that abdominal rectopexy is better than perineal
approaches, the latest Cochrane review of 15 studies concludes that there is no
difference in recurrence rates or postoperative complications. If constipation is a
main symptom, bowel resection may help (282).
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