Fecal incontinence causes
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Kiran Singh, M.D. [2]
Causes
Life Threatening Causes
Common Causes
- Aging
- Acute gastroenteritis
- Constipation
- Fecal impaction
- Irritable bowel syndrome
- Ulcerative colitis
Causes by Organ System
Causes in Alphabetical Order
Causes
Constipation
Constipation is the most common cause of fecal incontinence. Constipation causes prolonged muscle stretching and leads to weakness of the intestinal muscles. After a certain point, the rectum will no longer close tightly enough to prevent stool loss, resulting in incontinence.[1]
Muscle damage
Fecal incontinence can be caused by injury to one or both of the ring-like muscles at the end of the rectum called the internal and external anal sphincters. During normal function, these sphincters help retain stool. In women, damage can occur during childbirth. The risk of injury is greatest when the birth attendant uses forceps to help the delivery or does an episiotomy. Hemorrhoid surgery can damage the sphincters as well. A pelvic tumor that grows in or becomes attached to the rectum or anus also can cause muscle damage, as can surgery to remove the tumor. Although anal sex resulting in repeated injury to the internal anal sphincter can lead to incontinence, the threat is relatively small.[2] One study among 14 anoreceptive homosexual men and ten non-anoreceptive heterosexual men showed that anoreceptive homosexual men have decreased anal canal resting pressure relative to non-anoreceptive heterosexual men and no associated fecal incontinence.[3] Another study among forty anoreceptive homosexual men and ten non-anoreceptive heterosexual men found a very significant increase in fecal incontinence (fourteen, or 35% amongst the anoreceptive men, and one, or 10% in the non-anoreceptive sample) amongst the the anoreceptive sample.[4]
Nerve damage
Fecal incontinence can also be caused by damage to the nerves that control the anal sphincters or to the nerves that detect stool in the rectum. Damage to the nerves controlling the sphincter muscles may render the muscles unable to work effectively. If the sensory nerves are damaged, detection of stool in the rectum is disabled, and one will not feel the need to defecate until too late. Nerve damage can be caused by childbirth, long-term constipation, stroke, and diseases that cause nerve degeneration, such as diabetes and multiple sclerosis.
Loss of storage capacity
Normally, the rectum stretches to hold stool until it is voluntarily released. But rectal surgery, radiation treatment, and inflammatory bowel disease can cause scarring, which may result in the walls of the rectum becoming stiff and less elastic. The rectum walls are unable to stretch as much and are unable to accommodate as much stool. Inflammatory bowel disease also can make rectal walls very irritated and thereby unable to contain stool.
Diarrhea
Diarrhea, or loose stool, is more difficult to control than solid stool that is formed. Where diarrhea is caused by temporary problems such as mild infections or food reactions, incontinence tends to last for a period of days. Chronic conditions, such as Irritable Bowel Syndrome, or Crohn's disease can cause severe diarrhea lasting for weeks or months until successful treatment can be found.
Pelvic floor dysfunction
Abnormalities of the pelvic floor can lead to fecal incontinence. Examples of some abnormalities are decreased perception of rectal sensation, decreased anal canal pressures, decreased squeeze pressure of the anal canal, impaired anal sensation, a dropping down of the rectum (rectal prolapse), protrusion of the rectum through the vagina (rectocele), and generalized weakness and sagging of the pelvic floor.
Other causes
Fecal incontinence can have other causes including one or a combination of the following:
- Excretory problems
- Fecal impaction
- Diseases, drugs, and indigestible dietary fats that interfere with the intestineal absorption. Respective examples include cystic fibrosis, orlistat, and olestra.
- Lateral internal sphincterotomy (Surgical procedure for helping Anal fissures heal)
- Seizure
- Drug Induced - Pergolide, Pramipexole