What is fecal incontinence?

Fecal incontinence is the impairment of bowel control leading to involuntary defecation. It is also referred to as bowel incontinence or anal incontinence. Normal continence depends on both voluntary and involuntary mechanisms. This is discussed further under defecation. Conscious control of the anal sphincter allows it to relax and the action of the muscles in the wall of the colon and rectum pushes out the feces. With fecal incontinence, the ability to control this mechanism is disrupted.

Fecal incontinence is sometimes confused with diarrhea and often a patient with fecal incontinence incorrectly reports it as diarrhea due to embarrasment. Diarrhea is frequent bowel movements, more than 3 times a day, and often passing more than 200ml/200g of stool in a 24 hour period. While some cases of diarrhea can be severe and fecal incontinence may be present, it is usually temporary. In most cases of diarrhea, a person is able to control the need to defecate until they can reach a suitable facility. With fecal incontinence, a person is unable to restrain themselves for even a few minutes and may not even be aware of soiling the underwear.

Signs and Symptoms of Fecal Incontinence

The presentation of fecal incontinence varies and this is the reason that patients with milder cases often do not consider is at incontinence. In these cases, a person may pass off the incident as a minor mishap or ‘anal leakage’.

Mild fecal incontinence can present as a passing small amounts of hard or watery stool when passing gas (flatus). In more severe cases, a person is unable to control the bowel movement at all and passes out a full volume of stool in their underwear.

Other gastrointestinal features are almost always present. This includes :

In addition, a person may also report :

  • Offensive smelling flatus
  • Inability to ‘wipe’ completely
  • Constant bad odor from the anal region

All of these symptoms are a consequence of fecal incontinence. Other signs and symptoms may be related to the cause of fecal incontinence.

Fecal Incontinence Meaning

Fecal incontinence is a difficulty with bowel control to varying degrees often leading to a person soiling their clothing/underwear before reaching the toilet. A person may be unaware of the occurrence in conditions like dementia and it may go by unnoticed until a caregiver attends to the person. However this should not detract from the fact that fecal incontinence can affect any person of any age with normal mental functioning.

Fecal incontinence is commonly seen in the elderly and is due to a host of age-related causes as well as chronic conditions that have progressed to the point of complications. In children, the inability to control bowel movements before 4 years of age should not be considered as fecal incontinence.

Encopresis is the tendency to pass stool in places other than the toilet and is a recurrent occurrence. It is often seen in children and may be a consequence of avoiding bowel movements (stool holding) leading to fecal impaction and incontinence. Encopresis is commonly associated with constipation in children and may also occur as a result of emotional causes.

Causes of Fecal Incontinence

Altered Bowel Movements

Severe diarrhea and chronic constipation are two of the more common causes of fecal incontinence.

In severe diarrhea, a person may be unable to reach a toilet in time. FecalĀ  incontinence is usually acute and seen in severe infectious gastroenteritis. Passing small amounts of stool, particularly watery stool, may occur on its own or with passing gas or even during violent vomiting and retching.

Chronic constipation may lead to fecal impaction. The colon and rectum may stretch and compromise the integrity of the anal sphincter. Watery stool often leaks around the impacted mass and exits unknowingly and without any urge to have a bowel movement.

Anorectal Abnormalities

A range of anorectal diseases may lead to fecal incontinence. Hemorrhoids is a more common cause and fecal incontinence may also be seen with inflammatory bowel disease, particularly Crohn’s disease, and rectal prolapse. Congenital anorectal anomalies may also be a cause and fecal incontinence is often reported throughout life to varying degrees.

With anorectal abnormalities, the nerves controlling bowel movements, muscles controlling the sphincters and anatomical structure of the rectum and anus is affected.

Sometimes fecal incontinence is reported in irritable bowel syndrome despite the lack of any physical abnormalities. This may be related to an exaggerated defecation reflex coupled with abnormal activity of the autonomic system (voluntary control).

Obstetric Causes

Injury to the pelvic floor muscles and related nerves following childbirth or a hysterectomy may affect bowel control to varying degrees. This may also be seen following an episiotomy.

Neurological Causes

If the nerves controlling and regulating bowel control (refer to defecation control) are inflamed or damaged fecal incontinence may occur. This could also occur with neurological defects affecting the brain and higher mental functioning.

Some of these causes include :

  • Diabetic neuropathy – nerve damage in uncontrolled and long standing diabetes mellitus (sugar diabetes)
  • Dementia
  • Stroke
  • Multiple sclerosis
  • Any spinal cord lesions, especially of the lower end of the spinal cord (cauda equina)
  • Obstetric causes as mentioned above
  • After anorectal surgery like for hemorrhoids


Article reviewed by Dr. Greg. Last updated on June 6, 2012