[Diagnostic guidelines in diarrhea].

Acute diarrhea is usually short-lasting; therefore, diagnostic procedures are mainly concerning the degree of dehydration. With longer duration of high fever or bloody diarrhea, microbiologic stool tests are necessary. Proctosigmoidoscopy is indicated in case of dysenteric disease or suspected antibiotic-as-associated pseudomembranous colitis. In chronic diarrhea, the most important diagnostic procedure is a careful history. Side effects of drugs and food-related causes are especially noticeable, as are indices of an organic origin, e.g. unwanted weight loss or blood in the stools. Also, careful history and physical examination are essential for the decision about laboratory tests, tests of gastrointestinal function or endoscopy.