Fecal Incontinence or Accidental Bowel Leakage 2017-08-21T11:29:02-04:00



Accidental bowel leakage is the inability to control the bowels. Stool may leak from the rectum unexpectedly, sometimes while passing gas.

How common is this condition?
More than 5.5 million Americans have fecal incontinence. It affects people of all ages—children and adults. Fecal incontinence is more common in women and older adults, but it is not a normal part of aging.

Mechanism of bowel control

The anal canal is the lowest part of the bowel tract and is responsible for withstanding the downward movement (peristalsis) of the gut. In order to do so, it is surrounded by a ring of sphincter muscle called the internal and the external sphincter muscles. These muscles along with the sling muscle called the puborectalis sling help control bowel leakage. The internal sphincter and the sling muscle are always contracted whereas the external sphincter muscle contracts when the patient squeezes her rectal muscles to hold back gas or stool leakage.

Weakness of these muscles could predispose to accidental bowel leakage. Initially, it may start with gas leakage which itself could be extremely distressing but the worst is when there is actual leakage of formed stools.



Constipation is one of the most common causes of accidental bowel leakage. Constipation causes large, hard stools to become lodged in the rectum. Watery stool can then leak out around the hardened stool. Constipation also causes the muscles of the rectum to stretch, which weakens the muscles so they can’t hold stool in the rectum long enough for a person to reach a bathroom. This may also be associated with a rectocele (rectum bulging into the vagina) especially in women. Also, straining at a bowel movement could predispose to not only sphincter weakness but also vaginal prolapse (bulge) or even rectal bulging out of the opening.

Muscle Damage

Accidental bowel leakage can be caused by injury to the internal and external sphincters muscles. The sphincters keep the stools inside. When damaged, the muscles aren’t strong enough to do their job and stool can leak out. In women, the damage often happens when giving birth. The risk of injury is greatest if the doctor uses forceps to help deliver the baby or performs an episiotomy, which is a cut in the vaginal area to prevent it from tearing during birth. Hemorrhoid surgery can also damage the sphincters.

Nerve Damage

Fecal incontinence can be caused by damage to the nerves that control the anal sphincters or the nerves that sense stool in the rectum. If the nerves that control the sphincters are injured, the muscles don’t work properly and incontinence can occur. If the sensory nerves are damaged, they don’t sense that stool is in the rectum so you won’t feel the need to use the bathroom until stool has leaked out. Nerve damage can be caused by childbirth, a long-term habit of straining to pass stool, stroke, physical disability due to injury, and diseases that affect the nerves such as diabetes and multiple sclerosis.

Loss of Storage Capacity

Normally, the rectum distends to hold stool until you can get to a bathroom. But rectal surgery, radiation treatment, and inflammatory bowel disease can cause scarring that makes the walls of the rectum stiff and less elastic. The rectum then cannot stretch as much and fecal incontinence results. Inflammatory bowel disease also can irritate the rectal walls, making them unable to contain stool.


Diarrhea, or loose stool, is more difficult to control than solid stool because with diarrhea the rectum fills with stool at a faster rate. Even people who don’t have fecal incontinence can leak stool when they have diarrhea.

Pelvic Floor Dysfunction

Abnormalities of the pelvic floor muscles and nerves can cause fecal incontinence. Examples include:

  • impaired ability to sense stool in the rectum

  • decreased ability to contract muscles in the anal canal to defecate

  • dropping down of the rectum, a condition called rectal prolapse

  • protrusion of the rectum through the vagina, a condition called rectocele

  • general weakness and sagging of the pelvic floor

Childbirth is often the cause of pelvic floor dysfunction, and incontinence usually doesn’t appear until the mid-forties or later.


History: This is important as it tells us not only the frequency of bowel leakage but also how much is this affecting the patient’s quality of life. Patients typically fill out certain specific questionnaires at our office pertaining to fecal incontinence.

Examination:  Vaginal examination is important to make sure that there is no associated vaginal prolapse mainly rectocele (rectum bulging into the vagina). Also, this exam will help identify if the patient is constipated. Rectal examination indicates the sphincter weakness. Finally, a neurologic exam is important especially in patients with multiple sclerosis or stroke.

However, to make the appropriate diagnosis, specialized tests may be performed.

  • Stool diaries: These help understand the frequency of bowel movement, the type of stool passed and also the number of leakage episodes in a day.

  • Anal manometry checks the tightness of the anal sphincter and its ability to respond to signals, as well as the sensitivity and function of the rectum.

  • Anorectal ultrasonography evaluates the structure of the anal sphincters.

  • Proctography, also known as defecography, shows how much stool the rectum can hold, how well the rectum holds it, and how well the rectum can evacuate it.

  • Proctosigmoidoscopy allows doctors to look inside the rectum and lower colon for signs of disease or other problems that can cause fecal incontinence, such as inflammation, tumors, or scar tissue.

  • Anal electromyography tests for nerve damage, which is often associated with injury during childbirth.

Anal electromyography tests for nerve damage, which is often associated with injury during childbirth.


Interstim Neuromodulation

This has been approved by the FDA for the management of accidental bowel leakage. This involves the placement of a battery activated electrode near the bowel nerve S-3 nerve. The procedure is done through a buttock incision and is done in a surgicenter in an outpatient manner. It typically takes 30 minutes to perform and has very few complications. Nowadays this is preferred to surgical correction.


Surgery to repair the anal sphincter may be an option for women who have not responded to dietary treatment and pelvic floor therapy and especially those who have a torn sphincteric noted on anal ultrasound. The typical procedure involves repairing the internal and the external anal sphincter and is called Anal Sphincteroplasty. This is done through the perineum (vaginal opening).  The procedure takes about 1 hour to perform and most patients go home the next morning after an overnight stay.

Other treatments:

A colostomy may be indicated for people with severe fecal incontinence who haven’t been helped by other procedures. This procedure involves disconnecting the colon and bringing one end through an opening in the abdomen—called a stoma—through which stool leaves the body and is collected in a pouch. This is done in severe cases of bowel leakage where everything else has failed.

  • Diet

    Improve the stool consistency. If the stools are watery then avoid bowel irritants such as caffeine. If the stools are too hard then eating a lot of fiber and laxatives would help.

  • Exercise

    This helps a lot with optimizing bowel frequency. Specific pelvic floor exercises are mentioned below.

  • Medication

    If the bowel movements are loose, medicines such as Imodium or Lomotil are prescribed to slow down the bowel motility in order to improve the stool consistency.

  • Pelvic floor therapy

    This is a way to strengthen and coordinate the rectal muscles. Pelvic floor therapy uses electrical stimulation that helps with the rectal sphincter activity. This is usually done in the office on a weekly basis for 4-6 weeks.