Nursing home residence is by far the most prominent association with fecal incontinence, with a prevalence approaching 50%. In one major survey, urinary incontinence was the greatest risk factor for developing fecal incontinence, and fecal incontinence was the greatest risk factor for developing urinary incontinence. Immobility, dementia, and the use of physical restraints were also important risk factors. Specific diseases associated with fecal incontinence include diabetes, multiple sclerosis, Parkinson's disease, stroke, and spinal cord injury. The surgical procedures lateral internal sphincterotomy for anal fissure, fistulotomy, and ileal pouch reconstruction can result in fecal incontinence. Children who are born with congenital abnormalities, such as imperforate anus, often experience soiling for many years. Future studies to determine the prevalence and etiology of fecal and urinary incontinence will need to first define these conditions and eliminate referral bias. Epidemiologic investigations of both disorders should be performed jointly because the conditions are so often comorbid.