Fecal incontinence may occur temporarily during an occasional bout of diarrhea, but for some people, fecal incontinence is chronic or recurring. People with this condition may be unable to stop the urge to defecate, which comes on so suddenly that they don't make it to the toilet in time. This is called urge incontinence.

Another type of fecal incontinence occurs in people who are not aware of the need to pass stool. This is called passive incontinence.

Fecal incontinence may be accompanied by other bowel problems, such as:

• Diarrhea
• Constipation
• Gas and bloating

For many people, there is more than one cause of fecal incontinence.

Causes can include:

• Muscle damage. Injury to the rings of muscle at the end of the rectum (anal sphincter) may make it difficult to hold stool back properly. This kind of damage can occur during childbirth, especially if you have an episiotomy or forceps are used during delivery.
• Nerve damage. Injury to the nerves that sense stool in the rectum or those that control the anal sphincter can lead to fecal incontinence. The nerve damage can be caused by childbirth, constant straining during bowel movements, spinal cord injury or stroke. Some diseases, such as diabetes and multiple sclerosis, also can affect these nerves and cause damage that leads to fecal incontinence.
• Constipation. Chronic constipation may cause a dry, hard mass of stool (impacted stool) to form in the rectum and become too large to pass. The muscles of the rectum and intestines stretch and eventually weaken, allowing watery stool from farther up the digestive tract to move around the impacted stool and leak out. Chronic constipation may also cause nerve damage that leads to fecal incontinence.
• Diarrhea. Solid stool is easier to retain in the rectum than is loose stool, so the loose stools of diarrhea can cause or worsen fecal incontinence.
• Hemorrhoids. When the veins in your rectum swell, causing hemorrhoids, this keeps your anus from closing completely, which can allow stool to leak out.
• Loss of storage capacity in the rectum. Normally, the rectum stretches to accommodate stool. If your rectum is scarred or your rectal walls have stiffened from surgery, radiation treatment or inflammatory bowel disease, the rectum can't stretch as much as it needs to, and excess stool can leak out.
• Surgery. Surgery to treat enlarged veins in the rectum or anus (hemorrhoids), as well as more-complex operations involving the rectum and anus, can cause muscle and nerve damage that leads to fecal incontinence.
• Rectal prolapse. Fecal incontinence can be a result of this condition, in which the rectum drops down into the anus.
• Rectocele. In women, fecal incontinence can occur if the rectum protrudes through the vagina.

A number of factors may increase your risk of developing fecal incontinence, including:

• Age. Although fecal incontinence can occur at any age, it's more common in adults over 65.
• Being female. Fecal incontinence can be a complication of childbirth. Recent research has also found that women who take menopausal hormone replacement therapy are more likely to have fecal incontinence.
• Nerve damage. People who have long-standing diabetes or multiple sclerosis — conditions that can damage nerves that help control defecation — may be at risk of fecal incontinence.
• Dementia. Fecal incontinence is often present in late-stage Alzheimer's disease and dementia.
• Physical disability. Being physically disabled may make it difficult to reach a toilet in time. An injury that caused a physical disability also may cause rectal nerve damage, leading to fecal incontinence.

Complications of fecal incontinence may include:

• Emotional distress. The loss of dignity associated with losing control over one's bodily functions can lead to embarrassment, shame, frustration and depression. It's common for people with fecal incontinence to try to hide the problem or to avoid social engagements.
• Skin irritation. The skin around the anus is delicate and sensitive. Repeated contact with stool can lead to pain and itching, and potentially to sores (ulcers) that require medical treatment.