[Diagnostic strategy in constipation, including irritable bowel syndrome].

Constipation is not a disease but a symptom. Underlying causes include side effects of drugs, metabolic, endocrine, neurologic, psychiatric and intestinal diseases. Constipation is part of the so-called irritable bowel syndrome. The diagnosis is based on history, physical examination and a few laboratory tests. Second-line diagnostic procedures include endoscopy, colonic transit time and physiological investigations of the anorectum like anorectal manometry or defecography.