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Anal Fistula

What is an anal fistula?

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

Fistulas usually don’t go away without treatment.

What is the cause?

An anal fistula is usually caused by a bacterial infection in the anus. It may happen as a result of:

  • Injury to your anus
  • Frequent use of laxatives
  • Diseases of the intestines, such as Crohn's disease (inflammation of the intestines)
  • Childbirth
  • Other diseases or infections

What are the symptoms?

Symptoms may include:

  • Itching or irritated skin around your anus
  • Watery pus, sometimes mixed with blood, in or around your anus
  • Pain in the rectal area, especially when you have a bowel movement
  • Leaking of bowel movement

How is it diagnosed?

Your healthcare provider will ask about your symptoms and medical history and examine you. Tests may include:

  • An exam of the area around and inside your rectum. Your provider will put a lubricated and gloved finger gently into your rectum to try to see how deep the fistula is and find the opening at the other end of the fistula tunnel.
  • Anoscopy, which uses a small, lighted tube put into your rectum to examine the anal area
  • MRI, which uses a strong magnetic field and radio waves to show detailed pictures of the rectal area and the fistula
  • Ultrasound, which uses sound waves to show pictures of the rectal area and the fistula

You may have other tests to see if you have an inflammatory disease of the intestine, which may be the cause of the fistula.

How is it treated?

An anal fistula may be treated with surgery to open and drain the infected area. The surgery is called a fistulotomy.

  • Small fistulas may be treated in your healthcare provider's office. In some cases your provider may be able to use stitches and surgical glue to seal and heal the fistula instead of cutting it open.
  • If the fistula is large, you usually need surgery to close the fistula.

Before surgery you will be given medicine to keep you from feeling pain. After surgery, your provider will prescribe stool softeners and rest. Your provider may also prescribe antibiotics and pain medicine.

If the fistula is small and easy to treat, you may be better in a few days or weeks. If your fistula is deep or long and harder to treat, it may take more than 1 surgery and a longer time for the fistula to heal completely. If you have a medical problem like inflammatory bowel disease, you may keep getting fistulas.

How can I take care of myself?

To care for yourself at home after treatment:

  • Do these things to help keep your bowel movements soft:
    • Follow your healthcare provider's instructions for taking stool-softening medicines.
    • Drink plenty of water.
    • Add more fiber to your diet with whole-grain foods, bran, fruits, and vegetables.
  • After bowel movements, gently wipe the area around the anus with clean, moist pads. This will remove irritating particles and fluid from the anal area.
  • Soak in warm baths to help relieve pain and keep the area clean. Warm baths help bring more blood flow to the area. Blood brings infection-fighting cells and healing nutrients.

Follow your healthcare provider's instructions. Ask your provider:

  • How and when you will hear your test results
  • How long it will take to recover
  • What activities you should avoid and when you can return to your normal activities
  • How to take care of yourself at home
  • What symptoms or problems you should watch for and what to do if you have them

Make sure you know when you should come back for a checkup.

How can I help prevent an anal fistula?

There is no sure way to prevent anal fistulas. However, you may be able to help prevent them if you get treatment for any rectal problems, especially infections, right away.

Developed by RelayHealth.
Adult Advisor 2015.1 published by RelayHealth.
Last modified: 2014-09-23
Last reviewed: 2014-09-24
This content is reviewed periodically and is subject to change as new health information becomes available. The information is intended to inform and educate and is not a replacement for medical evaluation, advice, diagnosis or treatment by a healthcare professional.
Copyright ©1986-2015 McKesson Corporation and/or one of its subsidiaries. All rights reserved.
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