Anal Fistula

What is an anal fistula?

An anal fistula is an abnormal tunnel between the anal canal and the outer skin of the anus. The anus is the opening of the rectum where bowel movements (BMs) leave the body.

How does it occur?

An anal fistula can be caused by

• a bacterial infection in the tissue lining the anal canal (the usual cause)
• passing hard stool or having chronic diarrhea
• childbirth
• injury to the anus
• frequent use of laxatives
• diseases of the colon or rectum, such as diverticulitis (inflammation of small pouches in the wall of the intestines) or Crohn's disease (chronic inflammation of the bowel.

What are the symptoms?

Symptoms of an anal fistula may include:

• itching
• watery pus, sometimes mixed with blood
• irritated skin around the anus
• pain in the rectal area, especially when you have a bowel movement
• leakage of stool between bowel movements.

How is it diagnosed?

Your healthcare provider will ask about your symptoms and examine you. You may have 1 or more of the following tests or procedures:

• swab of the anus to test for infection, such as gonorrhea
• anoscopy, which is a procedure in which your provider puts an instrument with a light into the rectum to look at the anus and lower part of the rectum
• lower gastrointestinal (GI) series, which is an X-ray exam that uses a special fluid to show the intestines better on X-ray
• sigmoidoscopy or colonoscopy, which are exams of the bowel with a slim, flexible, lighted tube.

Tissue can be removed (biopsied) during the exams that use a scope. The tissue can be tested for infection and signs of disease, such as Crohn's, ulcerative colitis, or cancer.

How is it treated?

The anal fistula may be treated with a surgical procedure called a fistulotomy. Your healthcare provider will cut open the infected area so the fistula can drain.

Small or shallow fistulas may be treated in your healthcare provider's office after you are given a local anesthetic to numb the area. Larger fistulas must be treated under regional or general anesthesia. If the fistula goes through both anal sphincter muscles, you may need more than 1 surgery.

After a fistulotomy, your healthcare provider will prescribe stool softeners and rest. Your provider may also prescribe antibiotics and pain medicine.

In some cases, instead of surgery, your provider may use a gluelike chemical to plug the fistula canal.

How long will the effects last?

An anal fistula usually does not go away unless it is treated.

How can I take care of myself?

To care for yourself at home after surgery:

• Follow your healthcare provider's instructions.
• Use stool softeners if recommended by your provider.
• Drink plenty of water.
• Take warm baths to keep the anal area clean and to increase blood circulation to the area. Blood brings infection-fighting cells and nutrients to the area.
• After bowel movements gently wipe the area around the anus with clean, moist pads. This will remove irritating particles and fluid from around the area of the fistula.

How can I help prevent an anal fistula?

There is no known way to prevent an anal fistula. However, keeping your lower GI tract healthy by eating plenty of fiber might help.

Disclaimer: This content is reviewed periodically and is subject to change as new health information becomes available. The information provided is intended to be informative and educational and is not a replacement for professional medical evaluation, advice, diagnosis or treatment by a healthcare professional.

HIA File gase4002.htm Release 13/2010