Health's Book

Definition

Bowel incontinence is the loss of bowel control, leading to an involuntary passage of stool. This can range from occasionally leaking a small amount of stool and passing gas, to completely losing control of bowel movements.

Urinary incontinence, a separate topic, is the inability to control the passage of urine.

Symptoms

Fecal incontinence can result from a wide variety of medical conditions, including childbirth-related anal injuries, other causes of damage to the anus or rectum, and nervous system problems.

Vaginal-delivery childbirth is a major cause of fecal incontinence. In many cases, childbirth results in damage to the anal sphincter, which is the ring of muscle that closes the anus and keeps stools within the rectum until a person can find an appropriate opportunity to defecate. Nerve injuries during childbirth may also be a factor in some cases. A study in 2000 by the Brigham and Women's Hospital in Boston, Massachusetts, found that women who had episiotomies were at higher risk for postpartum fecal incontinence. Childbirth-related incontinence is usually restricted to gas, but for some women it involves the passing of liquid or solid stools.

The removal of hemorrhoids by surgery or other techniques (hemorrhoidectomies) can also cause anal damage and fecal incontinence, as can more complex operations affecting the anus and surrounding areas. Anal and rectal infections, as well as Crohn's disease, can lead to incontinence by damaging the muscles that control defecation. New-onset fecal incontinence can also be a sign of colorectal cancer. For some people, incontinence becomes a problem when the anal muscles begin to weaken in midlife or old age.

Dementia, mental retardation, strokes, brain tumors, multiple sclerosis, and other conditions that affect the nervous system can cause fecal incontinence by interfering with muscle function or the normal rectal sensations that trigger sphincter contraction and are necessary for bowel control. One study of multiple sclerosis patients discovered that about half were incontinent. Nerve damage caused by long-lasting diabetes mellitus (diabetic neuropathy) is another condition that can give rise to incontinence.