Fecal incontinence and/or constipation are frequent complaints in multiple sclerosis associated with urinary bladder dysfunction, incontinence, and/or retention. Total and segmental colonic transit were studied by determination of radiopaque markers, and anorectal function by anorectal manometry, in 16 multiple sclerosis patients clinically defined (with urinary bladder dysfunction shown by urodynamic examination). Fifteen multiple sclerosis patients had constipation and 14 had increased colonic transit time; ten multiple sclerosis patients had fecal incontinence and five had spontaneous rectal contractions. It is suggested that increased colonic transit and anorectal dysfunction were secondary to neurologic disorders just as urinary bladder dysfunction is due to neurologic disorders in multiple sclerosis.