Fecal incontinence is defined as continuous or recurrent loss of fecal material in individuals over 4 years of age. It results in the involuntary release of stool and gas from the rectum. Fecal incontinence can range from the occasional leakage of stool while passing gas to a complete loss of bowel control. It may involve stool that is solid, liquid or a simultaneous combination of both.

Food enters the digestive tract at the mouth and exits at the anus. Most nutrients are absorbed from food as it travels through the small intestine. Most water and salt are absorbed by the body during transport through the large intestine. What remains is waste material (stool) consisting of undigested food, unabsorbed water, bacteria, mucus and dead cells.

In normal digestion, stool enters the rectum where it is stored. The buildup of stool in the rectum triggers the surrounding muscles to tighten the anal sphincter (rings of muscles at the end of the rectum that hold in stool). Stool usually remains in the rectum until a bowel movement is voluntarily initiated.

Normal functioning of the rectum and anus are necessary to hold stool in the rectum until a person is ready to have a bowel movement. Fecal incontinence may occur when the:

• Anal sphincter is too weak to hold stool in the rectum
• Sensation of the rectum being full is lessened
• Rectum loses its ability to store stool

Fecal incontinence often involves messy contact between liquid or watery stool and the sensitive skin around the anus. This can cause pain and itching (pruritus ani). Such anal discomfort may be further aggravated by constant wiping of the area or use of substances that can irritate the skin.

In addition, patients with fecal incontinence due to pelvic floor dysfunction may also experience urinary incontinence (inability to control the bladder).

Estimating how many people experience fecal incontinence can be difficult because many people do not seek treatment out of embarrassment. According to the National Institutes of Health (NIH), more than 5.5 million Americans experience fecal incontinence. People of all ages are affected by the condition, although it is more common in women and older adults. Fecal incontinence is not considered a normal part of the aging process.