Anal Incontinence Causes and Diagnoses

Anal incontinence or accidental bowel leakage usually occurs because the anal sphincter and pelvic floor muscles are not functioning properly. The anal sphincter muscle is a circular muscle that surrounds the anal canal, and the pelvic floor muscles (levator ani) form a sling around the anal canal.

Both the anal sphincter and pelvic floor muscles help women control their stools. Damage to these muscles is usually attributed to childbirth and/or aging. The muscles may be torn or the nerves that help them function may be damaged leading to impaired function of the continence mechanism.

Sometimes, anal sphincter injuries are recognized in the delivery room; however, often they are not as obvious and don't become a problem until later in life. Many women may experience anal incontinence from loss of muscle strength as they get older.

Common risk factors for anal incontinence include:

Vaginal childbirth, especially if forceps are used to deliver the baby

Injury or infection of the anal sphincter
Diarrhea
Inflammatory bowel diseases
Surgery on the colon or anus
Pelvic radiation therapy
Rectal prolapse
Urinary incontinence

Evaluation:

If you have anal incontinence, a pelvic floor specialist in urogynecology or colorectal surgery can provide evaluation and treatment of your symptoms. To better evaluate your symptoms, a pelvic floor specialist might

Ask questions about when and how often you experience anal incontinence and the consistency of your stools;
Ask you to keep a bowel diary to keep track of how often you lose control of gas or bowel movement, your food and fiber intake, and how much you drink;
Perform a physical exam that can help identify other conditions that are related to your anal sphincter, such as urinary incontinence, pelvic organ prolapse, and rectal prolapse.

A urogynecologist or colorectal surgeon might also conduct tests that could include:

Endoanal or pelvic floor ultrasound to gain information about your anal sphincter and pelvic floor (levator ani) muscles
Anal manometry to evaluate the pressures in your anal canal
MRI defecography to evaluate the position of your internal organs (bowels, bladder, uterus) during straining and evacuation

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