Anal fistula repair

Published by Bupa's Health Information Team, May 2010.

This factsheet is for people who are planning to have anal fistula repair, or who would like information about it.

An anal fistula is a connection (tunnel-like structure) between the skin around the anus and the rectum. Anal fistula repair is an operation to close this connection.

You will meet the surgeon carrying out your procedure to discuss your care. It may differ from what is described here as it will be designed to meet your individual needs.

About anal fistula

You can get an anal fistula as a result of an infection or an abscess (collection of pus) in your anus. It can also be caused by conditions that affect the bowel such as Crohn's disease.

There are different types of fistula. Some have a single connection running from your rectum to your skin. Others branch into more than one opening. Sometimes they cross the muscles that control the opening and closing of your anus (sphincter muscles).

Symptoms and signs of anal fistula can be constant or may disappear for a time before returning. Symptoms of an anal fistula can include:

• pain and discomfort in and around the anus
  
• irritation of the skin around the anus
  
• a discharge of blood or pus from your anus

These symptoms aren't always caused by anal fistula but if you have them, see your doctor.

Diagnosis of anal fistula

Your GP will ask about your symptoms and examine you. He or she may also ask you about your medical history. Your GP will usually refer you to a specialist colorectal surgeon (a doctor who specialises in conditions that affect the bowel).

Your surgeon will examine your anus and rectum to diagnose an anal fistula. He or she may do a digital rectal examination (DRE) to examine the area. In this examination, your surgeon will insert a lubricated, gloved finger into your rectum and feel the texture of the skin.

Your surgeon may use a special telescope with a light on the end called a proctoscope to see inside your rectum. He or she may also use a fistula probe. This is a tiny instrument that will be inserted through the fistula. Your surgeon may perform these examinations under general anaesthesia. This means you will be asleep during the procedure.

You may be asked to have an ultrasound, CT or MRI scan to help find out how the fistula is linked to your sphincter muscles.

What are the alternatives to surgery?

Surgery is the main treatment for anal fistulas.

Preparing for anal fistula repair

Your surgeon will explain how to prepare for your operation. For example, if you smoke you will be asked to stop, as smoking increases your risk of getting a wound or chest infection, and slows your recovery. You may be given a laxative to take for a few days before your operation. This will help empty your bowels.

Anal fistula surgery is usually done under general anaesthesia. This means you will be asleep during the operation. It may be possible to have the operation under local anaesthesia. This will completely block feeling from the area and you will stay awake during the operation.

If you have a general anaesthetic, you will be asked to follow fasting instructions. This means not eating or drinking, typically for about six hours beforehand. However, it's important to follow your anaesthetist's advice.

You may need to stay in hospital for three to 10 days after the operation.

Your surgeon will discuss with you what will happen before, during and after your procedure, and any pain you might have. This is your opportunity to understand what will happen, and you can help yourself by preparing questions to ask about the risks, benefits and any alternatives to the procedure. This will help you to be informed, so you can give your consent for the procedure to go ahead, which you may be asked to do by signing a consent form.

You may need to have a bowel washout (an enema). You may be asked to wear compression stockings to help prevent blood clots forming in the veins in your legs and or have an injection of an anti-clotting medicine called heparin

About anal fistula repair

The exact operation you have will depend on the type of fistula you have - your surgeon will examine the fistula and decide the best way to treat it.

Fistulotomy

If the fistula is superficial, it can be 'laid open'. This is called a fistulotomy. The fistula is opened up so that it can heal from inside out. Sometimes it's necessary to leave a thread of, for example, suture material in the fistula tract. This is called a seton and may need to remain in place for some time. A dressing is usually worn over the fistula until it has fully healed.

Advancement flaps

Newer surgical procedures use 'advancement flaps'. In this technique, flaps are stretched over the opening of the fistula.

Protein-based glue or plug

Sometimes a special protein-based glue or plug is used. Glue is injected into the anal fistula. The plug is inserted into the fistula and stitched in place. The aim is to seal off the fistula where it joins with the bowel while still allowing any pus to drain out as the fistula heals and new tissue grows.

What to expect afterwards

You will need to rest until the effects of the anaesthetic have passed. You may need pain relief to help with any discomfort as the anaesthetic wears off.

You can begin to drink and eat, starting with clear fluids, when you feel ready.

On the morning after your operation, you will usually need to take a bath and soak off the dressing from your wound. It's normal to have some bleeding. Afterwards, your nurse will apply a new dressing.

You will need to have the wound re-dressed daily until it heals. Your nurse may arrange for a district nurse from your GP surgery to visit you at home. You will be given a letter to give to the district nurse, and a date for a follow-up appointment with your surgeon.

You may be prescribed a course of antibiotics and laxatives. If you're prescribed antibiotics it's important you finish the course.

You will need to arrange for someone to drive you home.

Recovering from anal fistula repair

If you need pain relief, you can take over-the-counter painkillers such as paracetamol or ibuprofen. Always read the patient information leaflet that comes with your medicine and if you have any questions, ask your pharmacist for advice.

General anaesthesia temporarily affects your co-ordination and reasoning skills, so you must not drive, drink alcohol, operate machinery or sign legal documents for 48 hours afterwards. If you're in any doubt about driving, contact your motor insurer so that you're aware of their recommendations, and always follow your surgeon's advice.

A district nurse will visit you daily to change the dressing and to check that the wound is healing properly. Your wound should heal within six weeks. You may be advised to have a bath or shower before your district nurse's visit. It may help to take a painkiller an hour beforehand, as having your dressing replaced can be uncomfortable. You may find it helpful to wear a sanitary pad to prevent any leakage from the wound staining your clothes.

You can go to the toilet with the dressing in place, but you should make sure that you carefully wash and dry the anal area afterwards.

You will need to take it easy during the first few days. Don't sit still for long periods or do too much walking. Follow your surgeon's advice about driving.

At your follow-up appointment, your surgeon will decide whether you need to continue with daily dressings. You will be given advice about going back to work and resuming other activities.

What are the risks?

Anal fistula operations are commonly performed and generally safe. However, in order to make an informed decision and give your consent, you need to be aware of the possible side-effects and the risk of complications.

Side-effects

Side-effects are the unwanted but mostly temporary effects you may get after having the procedure. You will feel sore and find it difficult to sit down at first. You may also notice some bleeding.

Complications

Complications are when problems occur during or after the operation. Specific complications of anal fistula operation are uncommon, but can include:

• infection - this can result in an anal abscess and further surgery may be needed
  
• damage to the sphincter muscles - this may affect your bowel control and can lead to faecal incontinence
  
• narrowing of the anal canal (the short, muscular tube that connects the rectum with the anus)
  
• re-occurrence - there is a chance that the fistula may come back

The exact risks are specific to you and differ for every person, so we haven't included statistics here. Ask your surgeon to explain how these risks apply to you.

For answers to frequently asked questions on this topic, see Common questions.

For sources and links to further information, see Resources.