Anal fistula surgery

What is anal fistula surgery?

An anal fistula is a tunnel or channel that develops between the skin near the anus and the bowel. This can have a number of unpleasant symptoms, and surgery, known as anal fistula surgery, is often undertaken to correct this. It is performed under general anaesthetic.

Why would you do it?

Anal fistula surgery is usually needed to treat anyone suffering from an anal fistula as they are unlikely to heal on their own. Anal fistulas are normally the result of an abscess around the anus, which when drained of the pus, leaves a small channel behind it.

Anal fistulas can be extremely unpleasant, and often cause discomfort. Surgery is nearly always required.

What does it involve?

Anal fistula surgery is carried out under general anaesthetic. There is more than one possible procedure and the most suitable will depend on individual cases.


  • A fistulotomy involves cutting the fistula open and allowing it to heal as a flat scar. This is the most common form of surgery.
  • This is the best choice of treatment for fistulas that don’t pass through the sphincter.
  • If the anal fistula does pass through the sphincter, then there is an increased risk of incontinence with a fistulotomy and other procedures might be preferred.

Seton techniques:

  • A seton is a piece of surgical thread that can be inserted into the fistula to keep it open.
  • This can be deployed to keep the fistula open for several weeks, allowing it time to drain and heal thus avoiding the need to make an incision.
  • Although this allows the fistula to heal, it does not cure it. To cure the fistula, it may be necessary to have numerous, tighter setons inserted to gradually cut through the fistula.

Advancement flap procedure:

  • This involves covering the entrance of the fistula to the bowel with a flap of tissue from the rectum.
  • This procedure means that the muscles around the anal sphincter do not need to be cut.

How to prepare for it

Leading up to the surgery, it might be necessary to stop taking certain medications. It is also likely that you will need to empty your colon with either a laxative or an enema before surgery. You will also need to stop eating and drinking a certain period prior to surgery. It is recommended that you have someone to drive you home after surgery.

Post-operative care

It is to be expected that there will be some bleeding and pain with your first bowel movement after surgery. It can help to make this less painful by adopting a high-fibre diet and taking stool-softeners the first few days after surgery.

Most patients will return to normal activities 1 to 2 weeks after surgery, but it will taken several weeks or a few months for the fistula to fully heal, depending on the individual case.

Here are some key post-operative care things to do after having anal fistula surgery:

  • Keep active – try to walk a little each day.
  • Diet – eat a high-fibre diet daily.
  • Stay hydrated
  • Painkillers may be prescribed for the first couple of weeks.
  • Keep the area operated on clean – warm baths are recommended.
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