Surgery

Anal fistula treatment

An anal fistula does not heal by itself, so can only be treated by surgery.

Surgery is done under general anaesthetic which means you will be asleep and will not feel anything.

Most people do not need to stay in hospital overnight, unless the surgery is more complex.

Before surgery

You go to a pre-assessment clinic before surgery, so we can:

  • check your health
  • ask you questions about your medical history and your medicines
  • talk to you about the surgery in more detail

Having surgery

During surgery, the infected tract is cut to stop unhealed pockets of infection from being trapped inside. If an abscess is found, this is cut open and drained first.

Before surgery it is not always possible to tell if your fistula runs through your sphincter muscles (muscles that open and close the anus). If these muscles are damaged, this can cause problems controlling when you poo (bowel incontinence).

To prevent any damage, the surgeon puts a stitch in your fistula rather than cut the sphincter muscles. This is called a ‘seton’.

A seton is a thread that is put through the fistula tract, out of the bottom and then tied in a knot outside. This allows the infection to drain and heal, without damaging your sphincter muscles.

Your surgeon might cut the part of your fistula that does not involve the sphincter muscles, and then put a seton in for the section that lies within the sphincter muscles. This means you might have a wound and a seton after surgery.

After surgery

If your surgeon inserts a seton, the stitch will need to stay in place for several weeks until all the pus and infection has drained away.

Sometimes it might need to be kept in longer than this. The stitch should not be painful and you can bathe and go to the toilet (open your bowels) as normal. It will not interfere with sex or pregnancy. 

Resource number: 0908/VER6
Last reviewed: March 2022
Next review: March 2025

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