Surgery for Anal Fistula
This webpage will give you information about surgery for an anal fistula. If you have any questions, you should ask your GP or other relevant health professional.
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) which has developed in your anal canal.The pus can drain away onto the 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 the skin, stays open.
What are the benefits of surgery?
If the operation is successful, you should no longer have any infection or pain.
Are there any alternatives to surgery?
Most anal fistulas do not heal on their own. Surgery is usually needed to treat the problem.
What does the operation involve?
Surgery for anal fistula is usually performed under a general anaesthetic. The surgery usually takes between a quarter of an hour and half an hour.
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).
Figure 1 - Different positions of an anal fistula:
a Below the sphincter muscle
b Through the sphincter muscle
c Above the sphincter muscle
- If the fistula is below or crosses the lower part of the sphincter muscles, your surgeon will cut the fistula open to the 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 (bowel opening onto the 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.
You should rest for the first few days, walking as little as possible, to help the 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, you should ask a member of the healthcare team or your GP for advice.
In a small number of cases, the fistula can come back.
An anal fistula can cause continued infection and pain. Symptoms usually get worse without an operation.
Author: Mr Jonathan Lund DM FRCS (Gen. Surg.) and Miss Gillian Tierney DM FRCS (Gen. Surg.)
Illustrations: LifeART image copyright 2011 Lippincott Williams & Wilkins. All rights reserved.
This document is intended for information purposes only and should not replace advice that your relevant health professional would give you.