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).
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.