Bowel dysfunction in multiple sclerosis

Bowel symptoms are seen in two thirds of multiple sclerosis (MS) patients, constipation and fecal incontinence, frequently coexisting, being the major symptoms. Since bowel symptoms are common in community, the need for precise definitions of pathology are stressed. Pathophysiological studies of bowel function are reviewed and the following hypothesis is suggested: Constipation is caused by a delay in colonic transit time, by a delay in the defecation reflex and by early external sphincter exitation. Fecal urgency/incontinence may be explained by impaired rectal sensation, not warning the patient to seek the toilet in time. Decrease in rectal compliance and in some patients abnormal rectal contractions may facilitate fecal expulsion and weak external sphincters allow leakage. Treatment options are commented and the need for treatment studies stressed.