Case 39: Abdominal pain

 

Case 39: Abdominal pain

CASE 39: ABDOMINAL PAIN

History

A 24-year-old student is referred to the gynaecologist on call from the emergency department with sudden onset of left iliac fossa pain which woke her at 2 am. She fell asleep again

but since 8 am the pain has been constant and is not relieved by ibuprofen or codydramol.

Her last period started 2 weeks ago and she reports no irregular bleeding or discharge. She has

no significant gynaecological history except for a termination of pregnancy at age 17 years. She

has been with her current boyfriend for 2 years and has used the combined oral contraceptive

pill (COCP) throughout that time. She says she has not had intercourse for the last 4 months

because her boyfriend has been travelling, but says that intercourse has never been painful.

On direct questioning she has felt nauseated but has not vomited. She has had no urinary

symptoms but has opened her bowels several times each day for the last 3 days, which is

unusual for her.

Examination

On examination she is apyrexial, her observations are normal and her abdomen is soft with

vague left iliac fossa tenderness but no signs of peritonism. Bimanual examination reveals

a normal-sized uterus with no adnexal tenderness or cervical excitation and no obvious

adnexal masses.

INVESTIGATIONS

Normal range

Haemoglobin 12.8 g/dL 11.7–15.7 g/dL

Mean cell volume 85 fL 80–99 fL

White cell count 6.4×109/L 3.5–11×109/L

Platelets 178×109/L 150–440×109/L

Sodium 142 mmol/L 135–145 mmol/L

Potassium 3.8 mmol/L 3.5–5 mmol/L

Urea 5.0 mmol/L 2.5–6.7 mmol/L

Creatinine 72 mmol/L 70–120 mmol/L

C-reactive protein 95 mg/L <5 mg/L

Questions

• What is the first investigation you would like to perform?

• What is your differential diagnosis if this test is negative, and how would you rule

out some of these diagnoses?100 Cases in Obstetrics and Gynaecology

94

ANSWER 39

Any woman of reproductive age with abdominal pain should always have a urinary pregnancy test, regardless of the date of her last menstrual period. In this case the test is negative.

The remaining differential diagnoses include:

• ovarian cyst

• pelvic inflammatory disease

• urinary tract infection or stone

• bowel-related cause.

There are no specific gynaecological symptoms or adnexal tenderness, which implies that the

pain is not gynaecological in origin. However during speculum examination it is prudent to

send swabs for chlamydial and gonorrhoeal infection opportunistically, in view of the high

background prevalence of sexually transmitted infection, especially in the 18–25-year-old

age group.

Ovulation pain (mittelschmirtz) or a corpus luteal cyst are very unlikely as the COCP inhibits the ovulatory cycle. However a transvaginal ultrasound scan will rule out an ovarian cyst

for certain.

Urine should be analysed for blood to rule out a renal stone, and for leucocytes and nitrites

to rule out infection.

Bowel habit is altered and the raised C-reactive protein suggests an inflammatory condition. As the onset is acute and not severe, the diagnosis is likely to be gastroenteritis.

This should be managed expectantly, with fluids, rest and simple analgesia. A stool culture

should be sent if the symptoms fail to resolve. Other inflammatory bowel conditions such

as Crohn’s disease and ulcerative colitis are rare causes to consider if the symptoms are

persistent or recurrent.

Irritable bowel syndrome is not associated with raised inflammatory markers, and is therefore not a differential diagnosis in this case.

KEY POINTS

• Gynaecological, urinary and bowel-related pathology can all be associated with

lower abdominal pain.

• A thorough and focused history is always important in making a correct diagnosis.