[Irritable colon and colonic disease due to laxatives].

Diarrhea of colonic origin is fairly common in irritable colon and after long term abuse of laxatives. This form of diarrhea causes difficulties not only in diagnosis but also in treatment. Irritable colon is a functional disorder sometimes involving other segments of the bowel. The term "irritable bowel disease" is thus more appropriate. Extraintestinal symptoms are in addition quite common. Although the diagnosis can be established with great reliability using an index we consider some laboratory tests, recto-sigmoidoscopy and abdominal sonography essential to rule out organic lesions. Therapy comprises (small) psychotherapy, dietary measures and eventually transient medication. Symptoms usually persist but tolerance of the disorder should be improved. Laxative-induced colonic dysfunction results usually from false assumptions about normal defecation. Loss of water and potassium deteriorates the symptomatology leading to a vicious circle. Alterations of neurons in the enteric nervous system of the colon can be the cause but eventually the consequence of chronic intake of laxatives. Hidden abuse of laxatives can cause great diagnostic difficulties. The therapy of choice is weaning which usually is only possible gradually. Cisapride can be a useful adjuvant.