Anal incontinence: Inability to hold feces in the rectum. This is due to failure of voluntary control over the anal sphincters. This failure results in the untimely passage of feces and gas.

There are many causes of anal incontinence, including congenital disorders of the spinal cord or anus; subsequent injuries to the rectum and anus; obstetric injuries during delivery; injury of the spinal cord; diabetic neuropathy (nerve damage); advanced Alzheimer disease or other forms of dementia; fecal impaction; and tumors.

Also called rectal or fecal incontinence.