[Functional diarrhea - pathophysiology, investigation and treatment].

The most important reason for functional diarrhea in clinical practice is diarrhea-predominant irritable bowel syndrome (IBS) which is characterized by chronic intermittent diarrhea and abdominal pain. The pathophysiology underlying IBS is complex and includes visceral hypersensitivity, abnormal gut motility and autonomous nervous system dysfunction as well as genetic and psychosocial factors. Treatment should be tailored to the individual's symptoms and involves general measures, pharmacological treatments, dietary interventions, psychotherapy and complementary and alternative approaches. The following manuscript will give an overview over pathophysiology, reasonable investigations and treatment of IBS.