Surgery for 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.

You should no longer have any infection or pain.

Most anal fistulas do not heal without surgery.

The operation is usually performed under a general anaesthetic but various anaesthetic techniques are possible. The operation 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.

If the fistula is below or crosses the lower part of the sphincter muscles (the muscles around your anal canal that control when you open your bowels), your surgeon will cut the fistula open to your skin and leave your 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 instead 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 special glue, clips or a plug made from pig-bowel tissue.

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.

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.

You should be able to return to work as soon as you can move about and sit freely.

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.

Most people make a full recovery and can return to normal activities. For a small number of people the fistula can come back.

Some complications can be serious and can even cause death.

General complications of any operation

• Pain
• Bleeding
• Infection of the surgical site (wound)
• Unsightly scarring of your skin

Specific complications of this operation

• Difficulty passing urine
• Involuntarily passing wind or loose faeces
• Bowel incontinence