The successful management of constipation and fecal incontinence in the elderly requires an understanding of colorectal function, careful delineation of the patient's complaint, and in selected patients, specialized studies of colonic and anorectal function. This article reviews (1) the prevalence and nature of lower bowel dysfunction in the elderly population: (2) colonic and anorectal physiologic changes that are associated with aging; (3) the causes, consequences, and approaches to the management of constipation in the elderly; and (4) the causes of fecal incontinence in this age group and the treatment available.