Fecal incontinence is the inability to control bowel movements, causing stool to leak unexpectedly from the anus. Fecal incontinence can range from occasional leakage of a small amount of stool while passing gas to a complete loss of bowel control.
A complex interaction of both voluntary and involuntary muscle sets, when working properly, allows the body to maintain continence. Proper functions of the muscles of the pelvic floor, along with both the internal and external anal sphincter muscles, are necessary to allow the body to store stool between bowel movements and void stool voluntarily at the appropriate time.
Because successful storage and voiding of stool is dependent on the interplay of multiple organ systems and anatomic structures, there are many risk factors for developing incontinence and many disease conditions which may also contribute. These include:
- Vaginal childbirth
- Prior pelvic surgery
- Prior anorectal surgery
- Damage to the sensory and muscular nerves that service the pelvis
- Stroke or other damage to the central or spinal nerves that service the pelvis
- Chronic inflammatory conditions of the gut, such as ulcerative colitis and Crohn's disease
- Infectious and other types of diarrhea
- Urogenital conditions in both men and women
- Many other conditions
In order to diagnose the cause of fecal incontinence, a provider may order one or more diagnostic tests, including:
- Anal manometry: This test is conducted with a short, flexible tube in the anus and rectum. It measures the strength of the anal sphincters and rectal sensation.
- Anorectal ultrasound: A small, balloon-tipped ultrasound probe is placed in the rectum. The probe uses high-frequency sound waves to create images of the anal sphincters.
- Defecography: A video x-ray of the area around the anus and rectum is taken while the patient coughs, squeezes the "cheeks" of the buttocks together, and defecates.
- MRI: Magnetic resonance imaging, or MRI, uses radio waves and magnets to create images of internal organs. Ultrasound gel may be added to the rectum to make structures appear more clearly.
- Flexible sigmoidoscopy: A thin, flexible tube with a tiny video camera at the end is passed through the anus into the rectum and the lower part of the colon, called the sigmoid colon. The provider can identify inflammation, tumors, or scar tissue that may contribute to fecal incontinence.
- Anal EMG: Electromyography, or EMG, uses tiny electrodes to measure electrical activity of muscles. Anal EMG can identify nerve damage.
Treatment for fecal incontinence depends on the cause. It may include dietary changes, medications, special exercises to retrain the muscles of the pelvic floor, or surgery.