What Is Fecal Incontinence?
Fecal incontinence—also known as bowel incontinence—is the inability to control bowel movements, resulting in feces (stool) to leak out of the rectum. Fecal incontinence may be accompanied by other gastrointestinal problems, including:
In the majority of adults, fecal incontinence only occurs during an occasional bout of diarrhea. However, some patients live with chronic incontinence, which can be broken down into two categories:
- Urge incontinence: Patients are unable to resist the very sudden urge to defecate in time to make it to the restroom
- Passive incontinence: Patients do not get the sensation that they need to know when to go to the restroom
Groups at risk for developing fecal incontinence include:
- Middle-aged and older adults
- Patients with dementia
- Patients with nerve damage
- Physically disabled patients
What Are the Causes of Fecal Incontinence?
For many patients, there may be more than one cause for fecal incontinence.
Causes may include:
- Chronic constipation. A backup of hard, dry feces lodged in the rectum can stretch and weaken the walls of the intestine. This can allow watery feces to move around in the hard stool and leak out of the anus. Chronic constipation may also cause nerve damage that leads to fecal incontinence
- Loose feces is harder to retain in the rectum than hard feces, which can lead to leakage
- Loss of space in the rectum. Loss of storage space in the rectum can occur when the walls of the intestine are scarred or hardened due to radiation, surgery or inflammatory bowel disease. As a result, the walls are unable to stretch, and feces may leak out
- Muscle damage. Injury to the anal sphincter—which typically happens during childbirth—can make it challenging to keep feces in
- Nerve damage. Injury to the nerves that cause the urge to defecate or those that control the anal sphincter can lead to leakage. Nerve damage may be the result of childbirth, trauma or disease, such as multiple sclerosis
- Rectal prolapse. Rectal prolapse occurs when the rectum drops down through the anus
- In women, fecal incontinence can also be due to the rectum protruding the vaginal wall
- Surgery to treat enlarged veins in the anus/rectum (hemorrhoids). Surgery to treat hemorrhoids may result in muscle or nerve damage
How Is Fecal Incontinence Diagnosed?
Tests to confirm the diagnosis of fecal incontinence include:
- Anal manometry. A small, flexible tube with a balloon at the end is inserted into the rectum. The balloon is then inflated, and the pressures of the muscles and the neural reflexes are recorded and evaluated
- Anorectal ultrasonography. A wand-shaped instrument is inserted into the anus to produce a video image of the rectum
- Balloon expulsion. A small balloon is inserted into the rectum and filled with water. Patients are then asked to secrete the balloon. The amount of time that it takes for the balloon to exit the body is recorded and assessed
- A small, flexible tube with a camera at the end is inserted into the anus to view the inside of the rectum and lower intestine for any abnormality
- Digital rectal exam (DRE). A physician inserts a gloved, lubricated finger into the anus to feel for any abnormality and evaluate anal sphincter strength
- Flexible sigmoidoscopy. A small, flexible tube with a camera at the end is inserted into the last portion of the colon known as the sigmoid colon to search for abnormality
- Magnetic resonance imaging (MRI). MRI produces clear images of the sphincter to check for any deformity in the muscles during defecation
- X-ray images are taken during a bowel movement on a special toilet to measure how much feces the rectum is able to hold
How Is Fecal Incontinence Treated?
Treatment for fecal incontinence may include:
- Taking medications, such as an anti-diarrheal (e.g., Imodium®), bulk laxatives (e.g., Citrucel®) or injectibles inserted into the anal canal
- Dietary changes, including eating more fiber and drinking more fluids
- Biofeedback exercises to increase muscle strength
- Sacral nerve stimulation (SNS), which uses an implanted device to send extra signals to the nerves that control the bowel
- Surgery, which is typically required for fecal incontinence only when correcting an underlying condition, such as rectal prolapse or sphincter trauma from childbirth