What is an anal fistula?
An anal fistula is an abnormal connection between the lining on the inside of your anal canal (back passage) and the skin near your anus. Most anal fistulas are caused by an abscess (a collection of pus) that has developed in your anal canal. The pus can drain away onto your skin on its own or by an operation. A fistula happens when the track, made by the pus on the way to the surface of your skin, stays open.
What are the benefits of surgery?
You should no longer have any infection or pain.
Are there any alternatives to surgery?
Most anal fistulas do not heal without surgery.
What does the operation involve?
The operation is usually performed under a general anaesthetic and usually takes 15 to 30 minutes. To lessen the risk of bowel incontinence (when you pass a bowel movement without wanting to) your treatment may involve several operations over a number of months.
The type of surgery you need will depend on where the fistula is (see figure 1). If the fistula is below or crosses the lower part of the sphincter muscles, your surgeon will cut the fistula open to your skin and leave the wound open so that it can heal with healthy tissue. If the fistula has branches that pass through the upper part of the sphincter muscles, your surgeon may place a special stitch (called a seton stitch) in the fistula to allow pus to drain easily.
The fistula may be suitable for treatment with a plug made from pig-bowel tissue. Your surgeon will not need to make a cut in the sphincter muscle.
If the fistula reaches above your sphincter muscles, you may need to have a temporary colostomy (your large bowel opening onto your skin). However, this is not common.
What complications can happen?
1. General complications
- Unsightly scarring
2. Specific complications
- Difficulty passing urine
- Involuntarily passing wind or loose faeces
- Bowel incontinence
How soon will I recover?
You should be able to go home the same day or the day after.
Rest for a few days, walking as little as possible, to help your wound to heal. The wound often takes several weeks to heal completely and you may need to wear a pad until then.
Regular exercise should help you to return to normal activities as soon as possible. Before you start exercising, ask the healthcare team or your GP for advice.
For a small number of people, the fistula can come back.
An anal fistula can cause continued infection and pain. Symptoms usually get worse without surgery.
Author: Mr Jonathan Lund DM FRCS (Gen. Surg.), Illustrations: Medical Illustration Copyright © Medical-Artist.com
This document is intended for information purposes only and should not replace advice that your relevant health professional would give you.