Chronic Diarrhea: Diagnosis and Management

Lawrence R. Schiller; Darrell S. Pardi; Joseph H. Sellin


Clin Gastroenterol Hepatol. 2017;15(2):182-193. 

In This Article

When Is Diagnostic Testing Indicated?


11. Testing should be done in the presence of alarm features, when the differential diagnosis can be effectively distinguished on the basis of test results, or when the differential diagnosis remains broad and initial testing will limit the number of additional tests needed. (2c)

12. For disorders without definitive diagnostic tests, therapeutic trials may be reasonable. (2c)

After interviewing and examining patients, the clinician may have a good idea of the likely cause of diarrhea. For some of these diagnoses, tests can confirm the diagnosis. For example, a patient with diarrhea, weight loss, and a tender abdominal mass might undergo computed tomography (CT) scanning and colonoscopy to establish a diagnosis of Crohn's disease. Testing also may be required to evaluate alarm features such as bleeding or weight loss. For other diagnoses no confirmatory tests are available. For example, a patient who developed diarrhea after cholecystectomy and had no alarm features might be tried on empiric bile acid binder therapy without further testing.

For many patients with chronic diarrhea, the pre-test probability of any specific diagnosis may not be high enough to allow focused testing or empiric therapy. In such cases, the clinician could conduct preliminary testing to categorize the diarrhea as discussed below and limit the differential diagnosis and subsequent testing. This approach has not been tested formally for chronic diarrhea; it is of value in guiding the evaluation of acute infectious diarrhea.[45]