Diagnosis

Your doctor will ask questions about your condition and perform a physical exam that usually includes a visual inspection of your anus. A probe may be used to examine this area for nerve damage. Normally, this touching causes your anal sphincter to contract and your anus to pucker.

Medical tests

A number of tests are available to help pinpoint the cause of fecal incontinence:

• Digital rectal exam. Your doctor inserts a gloved and lubricated finger into your rectum to evaluate the strength of your sphincter muscles and to check for any abnormalities in the rectal area. During the exam your doctor may ask you to bear down, to check for rectal prolapse.
• Balloon expulsion test. A small balloon is inserted into the rectum and filled with water. You'll then be asked to go to the toilet to expel the balloon. If it takes longer than one to three minutes to do so, you likely have a defecation disorder.
• Anal manometry. A narrow, flexible tube is inserted into the anus and rectum. A small balloon at the tip of the tube may be expanded. This test helps measure the tightness of your anal sphincter and the sensitivity and functioning of your rectum.
• Anorectal ultrasonography. A narrow, wand-like instrument is inserted into the anus and rectum. The instrument produces video images that allow your doctor to evaluate the structure of your sphincter.
• Proctography. X-ray video images are made while you have a bowel movement on a specially designed toilet. The test measures how much stool your rectum can hold and evaluates how well your body expels stool.
• Colonoscopy. A flexible tube is inserted into your rectum to inspect the entire colon.
• Magnetic resonance imaging (MRI). An MRI can provide clear pictures of the sphincter to determine if the muscles are intact and can also provide images during defecation (defecography).