Diagnostic Work-up

Diagnostic Work-up• There is no specific

laboratory or imaging test to diagnose irritable bowel syndrome.

• Currently the diagnosis of IBS relies on meeting Rome II inclusion criteria and excluding other illnesses based on history, physical exam, and laboratory testing.

Diagnostic Work-up

• Rome II Criteria for Diagnosis of Irritable Bowel Syndrome (2006)– Recurrent abdominal pain or discomfort at least 3

days per month in the last 3 months associated with 2 or more of the following:• Improvement/relief with defecation• Onset associated with a change in frequency of stool• Onset associated with a change in form (appearance)

of stool

Diagnostic Work-up

• Symptoms not typical of IBS:– New onset after age 50– Weight loss– Rectal bleeding– Fever– Nocturnal diarrhea– Diarrhea that is

persistent after a 48-h fast

Diagnostic Work-up

• Lab studies may include the following: – CBC count with

differential to screen for anemia, inflammation, and infection

– Erythrocyte sedimentation rate

– Stool Exam

Diagnostic Work-up

• The following selected studies are directed by history:– Breath testing: Screen for lactose intolerance.– Thyroid function tests: Screen for hyperthyroidism

or hypothyroidism.– Serologies or small bowel biopsy for celiac

disease: Consider, especially in diarrhea-predominant IBS.

Diagnostic Work-up

• Gallbladder ultrasonography: Consider this test if the patient has recurrent dyspepsia or characteristic postprandial pain.

• Double-contrast barium enema: Screen for neoplasm and inflammation.

Diagnostic Work-up

• Colonoscopy - Indicated for patients with warning signs, such as bleeding; anemia; chronic diarrhea; older age; history of colon polyps; cancer in the patient or first-degree relatives; or constitutional symptoms, such as weight loss or anorexia.