Anal fistula - Treatment 

Treating an anal fistula 

Waiting times

If your GP refers you for treatment, you have the right for any non-emergency treatment to start within a maximum of 18 weeks.

If this is not possible, the NHS must take all reasonable steps to offer you a range of suitable alternative providers. 

Read about the NHS Constitution and NHS waiting times.

Surgery is usually necessary to treat an anal fistula because very few will heal by themselves.

The aim of surgery is to heal the fistula while avoiding damage to the sphincter muscles (the ring of muscles that open and close the anus). Damage to the sphincter muscles could lead to bowel incontinence, where you do not have control over your bowels.


Surgery for an anal fistula is usually carried out under a general anaesthetic, where you are unconscious and cannot feel anything. In some cases, a local anaesthetic is used, where you are conscious but the area being treated is numbed so that you do not feel any pain.

Some of the different types of anal fistula surgery are explained below. The type of surgery you have will depend on the position of your fistula. In all cases, your surgeon will be able to explain the procedure to you in more detail.


A fistulotomy is the most commonly used type of anal fistula surgery. It is used in 85–95% of cases of fistulae.

A fistulotomy involves cutting open the whole length of the fistula, from the internal opening to the external opening. The surgeon will flush out the contents and flatten it out. After one to two months, the fistula will heal into a flat scar.

To access the fistula, your surgeon may have to cut a small portion of the anal sphincter muscle. However, this will depend on the position of the fistula. Your surgeon will make every attempt to reduce the likelihood of bowel incontinence.

Seton techniques

Your surgeon may decide to use a seton during your surgery. A seton is a piece of surgical thread that is left in the fistula tract, often for several months, to keep the tract open. This allows it to drain properly before it heals.

This may be considered if you are at high risk of developing incontinence, for example because your fistula crosses your sphincter muscles.

It is also sometimes used to allow secondary tracts to heal before further surgery is carried out on the main tract. It can also be used to divide the sphincter muscle, which allows it to heal between operations.

If your surgeon is planning to use a seton, they will discuss this with you. In some cases, it may be necessary to have several operations to treat your fistula using seton techniques. 

Advancement flap procedures

Advancement flap procedures may be considered if your fistula is complex, or if there is a high risk of incontinence.

An advancement flap is a piece of tissue that is removed from the rectum or from the skin around the anus.

During surgery, the fistula tract is removed (a procedure called fistulotomy). The advancement flap is then attached to where the internal opening of the fistula was.

Advancement flap procedures are thought to be effective in around 70% of cases.

Bioprosthetic plug

A bioprosthetic plug is a cone-shaped plug made from human tissue. It can be used to block the internal opening of the fistula. Stitches are used to keep the plug in place but the external opening is not completely sealed so that the fistula can continue to drain. New tissue then grows around the plug to heal it.

However, this procedure can sometimes lead to a new abscess forming or the plug being pushed out of place.

Read the National Institute for Health and Clinical Excellence (NICE) guidance on closure of anal fistula using a suturable bioprosthetic plug (PDF, 60KB).

Two trials that used bioprosthetic plugs have reported success rates of over 80%. However, there is still uncertainty over the reoccurrence rates and long-term outcomes.

Non-surgical treatments

Fibrin glue

Fibrin glue is currently the only non-surgical option for treating fistulae. The fibrin glue is injected into the fistula to seal the tract. The glue is injected through the opening of the fistula, and the opening is then stitched closed.

Fibrin glue may seem an attractive option as it is a simple, safe and painless procedure. However, the long-term results for this treatment method are poor. For example, one small study had an initial success rate of 77%, but after 16 months only 14% of people were still successfully healed.

Ongoing research

Several clinical trials are currently taking place to compare the different types of treatment for anal fistulae, and you may be asked to take part in one.

Read more information about taking part in a clinical trial.

If you are interested, you will be given information about the particular trial and you will be asked for your consent. Before giving your consent, make sure that you are fully aware of everything the trial involves, and feel free to decline if you do not wish to take part.

Read a list of current clinical trials for anal fistula.

Page last reviewed: 11/04/2012

Next review due: 11/04/2014


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The 8 comments posted are personal views. Any information they give has not been checked and may not be accurate.

Callyho84 said on 03 April 2014

I had my first follow up appointment last week - about 3 months after my Seton was placed. Really quick exam and my surgeon said the healing is looking good. Next step is that I need to have an MRI to see what my fistula is up to - how deep it is, what muscles are involved etc. then they will decide which is the best next surgery to do - fistulotomy, advancement flap or bio-prosthetic plug. I will post again after the MRI!

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tippy1 said on 03 March 2014

I just had a seton inserted on 28 Feb following a peri anal abcess. I am glad I have found these comments as although I discussed with my surgeon, you don't really know what to expect after surgery. You do not know who to turn to with any questions. My main pain seems to be from the site of the abcess which is still tender (this was drained on 15 Jan and packed for about 5 weeks) the seton is uncomfortable and I am finding it awkward going to the loo. I am an office worker and my job involves sitting all day which is very painful but I don't know how long I should reasonably stay off as feel ok otherwise. Any tips? I do feel as if this is dominating my life at the moment.

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Callyho84 said on 26 January 2014

Hi there, I also had surgery on my fistula in December 2013 and had a seton fitted.
This was my third surgery - the first two were both 'emergency' surgery to open up a peri anal abscess and this latest one is the first scheduled attempt at rectifying the fistula problem that developed from said abscess.

I would agree that I don't feel like I was given enough information prior to my surgery. I was told that if the fistula is too deep then I would need a seton, but didn't really understand what it was or how it worked. Needless to say, I was a little shocked and upset when I got home and discovered that I had what looks like an elastic band tied in a loop through my bottom and then out through the surgical opening in my skin!

If you are reading this before surgery then well done for doing some research. Make sure you ask lots of questions to your surgeon before the procedure, I didn't see mine after and wasn't given any info.

After the initial shock of the seton I have not found recovery to be too bad. Similarly to the post below I had sharp shooting pains for a while as the surgical opening healed. I'm about 6 weeks in now and have very little pain, the wound is healed as much as it can be with the seton in it and I just get some oozing. I use non adherent dressings which I can tuck in between my cheeks to soak up any mess. I find this dryer and more comfortable than sanitary towels. I read that oil of oregano is good for healing so I take tablets of that daily (I worry I smell like a pizza but it's worth a try) and I take vitamin C, try to eat healthily. I use moist toilet tissues and try to have lots of baths.

My next clinic appointment is in March and I have no idea what happens next - I will update. I have read lots of horror stories so I wanted to share that my experience has been ok so far - a pain in the bum, but ok! Good luck all!

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The Birch said on 29 December 2013

I had suffered for years until I was referred to my existing surgeon. A seton was inserted in February 2012. I thought it was only going to be for 3 months, but due to slow healing and a number of cancelled follow up appointments I am only now having the bio prosthetic plug fitted (tomorrow - 30/12/2013). In addition to the fistula I had an abscess, which I am confident has healed, so I hope this final procedure will do the trick. Whilst the seton has been in place I have suffered with discomfort and reoccurring bursting. I hope the plug will stop the pain and infection and bursting. I hope there is light at the end of the tunnel. I have read about the problems with surgery, so if this works then the time taken and discomfort will have been worthwhile. I have been disappointed with the lack of information from the medical profession about what to expect regarding post medical procedures, I think patients need to be better prepared. I hope to update in the future with a positive outcome and a healed fistula - I'll be like a new man !

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Chandra123 said on 29 December 2013

I had Fistulotomy using Seton techniques on 17 December 2013. After the operation I was given a letter to take to my GP's nurse to check my wound. Strangly, no one from the hospital given me any feedback about the operation. The GP nurse was useless and didn't know anything about the Seton. I am very reluctant to go back to my GP nurse and don't know where to get information about Seton. How long do I have to keep the Seton, who is qualified to remove it when required etc. I would be grateful if anyone could let me know where I could these information. By the way, I am computer programmer and my job involves in sitting in front of the computer more than 8 hours a day. At the moment I can't sit more than a hour and my bum gets hurting. Any advice would be greatly appreciated.

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Carly L said on 27 December 2013

I can swear by a portable bidet and cotton wool pads which I place over the wound as the edges of the seton often dig into my skin. I am nearly 8 weeks into my three months and I have my good and bad days. I only had a week off work with the operation and I manage but the bad days are a bit of a struggle. I also get strange aching down into my thigh on the side where the wound is and my leg sometimes aches too. I also often feel like I am carrying a lead weight in my bottom cheek!!! I had a perianal abscess in June prior to them discovering the fistula after 9 weeks of packing. Has now been six months and strangely my cousin has the same thing and has been off work for 9 months and is on his fourth operation at the end of Jan. My surgeon told me on the day of the seton fitting that he would see me in February and either tighten the seton or most likely fit a bio-plug. I will update here, glad to hear from a fellow sufferer. I wish there was an up to date site to share experiences on.

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danni68 said on 20 December 2013

Hi - I had same procedure done December 13th. Yesterday was follow up and I was convinced that it was worth going back to do a full fistulotomy. It frightens me but the surgeon feels pretty confident it will not affect continence. Looking for sites to chat with others who have had it done to know what to expect. So far my experience has been identical to yours described below. Any suggestions?

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Carly L said on 07 November 2013

I had an examination under anaesthetic and a seton put in place three days ago. I would like to tell anyone else experiencing this- it is not too bad. I have done a lot of research and looked at images that frightened me, however what I have had done is quite simple. Obviously there is pain and getting used to going to the toilet afterwards. I would describe the pain I feel as an open cut that stings and every so often I get a shooting pain up the wound site and my bottom cheeks ache. This pain is more uncomfortable than excruciating and only lasts for short periods. I was walking around slowly an hour after surgery and am still taking things slowly and listening to my body. I am hoping to go back to work a week after the procedure providing I have gotten used to my daily toileting routine-this is the most inconvenient part (obviously).

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Living with incontinence

A guide to coping with incontinence, with advice on travelling, sex, skincare, hygiene and emotional wellbeing.