Your Mayo Clinic care team
Mayo Clinic doctors trained in colon and rectal surgery, gastroenterology, and infectious disease, as well as wound care experts, work together to evaluate and treat people with anal fistula. If you have Crohn's disease or another medical condition, Mayo Clinic specialists will collaborate with your primary care doctor to form the best treatment plan.
Having all this expertise in a single place means that your care is discussed among the team, test results are available quickly, appointments are scheduled in coordination and the most highly specialized experts in the world are all working together for your health.
Knowing the complete path of an anal fistula is important for effective treatment. The opening of the channel at the skin (external) generally appears as a red, inflamed area that may ooze pus and blood. This external opening is usually easily detected.
Finding the fistula opening in the anus (internal opening) is more complicated. Mayo specialists use the latest technology, including the following:
- MRI is used for mapping the fistula tract and providing detailed images of the sphincter muscle and other structures of the pelvic floor.
- Endoscopic ultrasound uses high-frequency sound waves to identify the fistula, the sphincter muscles and surrounding tissues.
- Fistulography is an X-ray of the fistula after a contrast solution is injected.
Other options include:
- Fistula probe, an instrument specially designed to be inserted through a fistula
- Anoscope, a small endoscope used to view the anal canal
- Flexible sigmoidoscopy, a procedure to rule out other disorders such as ulcerative colitis and Crohn's disease
- An injected dye solution, which may help locate the fistula opening
A range of treatment options
Treatment of anal fistula depends on the fistula's location and complexity. The goals are to repair the anal fistula completely to prevent recurrence and to protect the sphincter muscles. Damage to these muscles can lead to fecal incontinence.
The options include:
- Fistulotomy. The surgeon cuts the fistula's internal opening, scrapes and flushes out the infected tissue, and then flattens the channel and stitches it in place. To treat a more complicated fistula, the surgeon may need to remove some of the channel. Fistulotomy may be done in two stages if a significant amount of sphincter muscle must be cut or if the entire channel can't be found.
- Advancement rectal flap. The surgeon creates a flap from the rectal wall before removing the fistula's internal opening. The flap is then used to cover the repair. This procedure can reduce the amount of sphincter muscle that is cut.
- Seton placement. The surgeon places a silk or latex string (seton) into the fistula to help drain the infection.
- Fibrin glue and collagen plug. The surgeon clears the channel and stitches shut the internal opening. Special glue made from a fibrous protein (fibrin) is then injected through the fistula's external opening. The anal fistula tract also can be sealed with a plug of collagen protein and then closed.
- Ligation of the intersphincteric fistula tract (LIFT). LIFT is a two-stage treatment performed at Mayo Clinic's campus in Florida for more-complex or deep fistulas. LIFT allows the surgeon to access the fistula between the sphincter muscles and avoid cutting them. A seton is first placed into the fistula tract, forcing it to widen over time. Several weeks later, the surgeon removes infected tissue and closes the internal fistula opening.
In cases of complex fistula, more-invasive procedures may be recommended, including:
- Ostomy and stoma. The surgeon creates a temporary opening in the abdomen to divert waste into a collection bag, to allow the anal area time to heal.
- Muscle flap. In very complex anal fistulas, the channel may be filled with healthy muscle tissue from the thigh, labia or buttock.