Anal Fistula

Overview

Anal fistulas are fairly common in people who have had an anal abscess. It's important to treat an anal fistula to reduce the chance of reinfection. Effective treatment also relieves accompanying symptoms. Patients treated for anal fistulas at Mayo Clinic benefit from skilled surgeons experienced in treating the most complex fistulas. Patients also have access to newer treatments, such as fibrin glue.

Diagnosis

Detecting the external opening of an anal fistula is usually easy, while finding the internal opening can be more complicated. Knowing the fistula's complete path is critical for effective treatment. Read more about anal fistula diagnosis.

Treatment Options

Because anal fistulas pass through the anal sphincter muscles, treatment must be delicately performed to reduce the risk of affecting bowel emptying. Each patient must be individually assessed for the best approach. Read more about anal fistula treatment. options

• Treatment in Arizona
• Treatment in Florida
• Treatment in Minnesota

About Anal Fistula

An anal fistula is a small tunnel (tract) with an internal opening in the anal canal and an external opening in the skin near the anus. It forms when an anal abscess that's drained (either on its own or via surgery) doesn't heal completely.

Anal fistulas are classified by their location in relation to the anal sphincter muscles. They are listed from most common to least common:

• Intersphincteric fistula. The tract begins in the space between the internal and external sphincter muscles and opens very close to the anal opening.
• Transphincteric fistula. The tract begins in the space between the internal and external sphincter muscles or in the space behind the anus. It then crosses the external sphincter and opens an inch or two outside the anal opening. These can wrap around the body in a U shape, with external openings on both sides of the anus (called a horseshoe fistula).
• Suprasphincteric fistula. The tract begins in the space between the internal and external sphincter muscles and turns upward to a point above the puborectal muscle, crosses this muscle, then extends downward between the puborectal and levator ani muscle and opens an inch or two outside the anus.
• Extrasphincteric fistula. The tract begins at the rectum or sigmoid colon and extends downward, passes through the levator ani muscle and opens around the anus. These fistulas are usually caused by an appendiceal abscess, diverticular abscess or Crohn's disease.