Chronic diarrhea. A practical approach.

Many patients who present with chronic diarrhea are not found to have an important organic disease. Most will have "functional" diarrhea. The history, the physical examination and the initial laboratory tests should lead to a provisional diagnosis, with respect to the organic or functional origin, and the location of disease in the small or the large bowel. Specific tests are then done to define particular organic causes of which malabsorption, inflammatory bowel diseases, carcinoma of the large bowel, parasitic infections, and metabolic disorders are most common. Patients with suspected functional diarrhea should be investigated at least by stool analysis, proctosigmoidoscopy, and barium enema. Functional diarrhea is common and these patients are no less susceptible to severe disease than is the rest of the population.