Please note, this page is printable by selecting the normal print options on your computer.
What is a fistula?
An anal fistula is a track between the skin on the outside of the buttock/anal area and the anal canal on the inside. There are many different types of fistulae from relatively simple to a complex branching network of tracks. Some type of fistulae may involve the muscles responsible for bowel control. The diagram below shows some different types of fistula:
What causes a fistula?
A fistula is usually the end result of a perianal abscess. An abscess results from an acute infection of a small gland just inside the anus, when bacteria or foreign matter enters the tissue through the gland.
Certain conditions – colitis or other inflammation of the intestine, for example – can sometimes make these infections more likely.
Does an abscess always become a fistula?
No. A fistula develops in about 50 percent of all abscess cases and there is really no way to predict if this will occur.
How will the operation help me?
Many different operations can be done for a fistula. You should discuss with your surgeon exactly what is planned for you. The aim is to cut out or lay open the infected track so as to promote healing from the base of the wound out to the surface, preventing unhealed pockets of infection from being left trapped inside. This healing can be a slow process, taking from a week or so up to several months. It is impossible to predict how long it will take in each individual case.
Further inpatient treatment may be required. This could involve a subsequent visit to the operating theatre to examine the wound under anaesthetic. Sometimes a stitch (called a Seton suture) is inserted to avoid dividing the muscle. This will be made of silk or a coloured rubber material. Your surgeon will explain this to you if it is needed in your case.
What preparation is needed before the operation?
You will probably come into hospital the day before or the morning of the operation. Routine blood tests are done before any operation if this has not been done at a “pre-assessment” visit. You will be asked questions about your general state of health by the nurses and doctors on the ward, and this is a good time to discuss any further questions you have about the operation. You may be given an enema to empty the rectum prior to surgery.
What will happen after the operation?
When you are awake and the effects of the anaesthetic have worn off you will be able to eat and drink and get up as you wish. It is advisable to stay on the ward until the effects of the anaesthetic have completely worn off. You will usually have a dressing in place around the entrance to the anus. This is to control any bleeding in the area. This will feel strange and possibly rather uncomfortable and it may make you feel that you want to open your bowels (although you are not likely to do so).
Some discomfort is to be expected. Painkillers are available: please ask your nurse if you need something to help with discomfort. You will normally have a bath or shower the next day and this will soak the dressing out (it may need a little gentle pull). It is quite possible that there will be some blood loss (do not be alarmed – this can make the water look very red!). Ask your nurse for assistance if you are concerned.
How will I open my bowels?
From the day after your operation you may be given laxatives. This will soften the stools and stimulate a bowel action. You may not open your bowels for a day or two, and when you do, some discomfort and a little bleeding may be present. This is to be expected. Regular painkillers as prescribed will help control discomfort and pain. It is often a good idea to take pain killers 30 minutes to 1 hour before you try to open your bowels.
Dressing your wound
Initially this will be done each day. You will be asked to take a bath or a shower or to use the bidet before each dressing is done. Having a bath or shower helps to remove the previous dressing and also to cleanse the external part of the wound. Experience has shown that it is very important that the fistula track heals from the base upwards towards the outside surface. To stop small pockets forming during the healing process, the nurse who is dressing your wound may gently insert a finger along the track at the time of the dressing. This is called Digitation. This procedure may be uncomfortable, but is essential to give your fistula wound the best opportunity for successful healing. Local anaesthetic gel will be used to help discomfort.
Your nurse will discuss the best form of pain relief with you if you need something to ease discomfort. It can be helpful to take a painkiller half an hour before your dressing is to be done.
How long will I be in hospital?
This varies between individuals, and depends on the type and complexity of the fistula. Many patients can be treated as a day case. Occasionally, for complex fistulas a few days in hospital will be necessary.
Your dressings at home
Before you go home your nurse will discuss with you how your dressings will be done at home. You will need to continue to have your dressing done each day. To start with the district nurse may visit to do the dressing for you, but you may find that you, or someone you live with, can manage (and this can be a lot more convenient as you will not need to wait in for the nurse). The dressing should be laid in the wound flat. “Packing” the wound with ribbon gauze is not required as it prevents drainage.
The dressing is done as a clean, not a sterile procedure. It is very important to insert a finger with anaesthetic gel into the wound each time that the dressing is done to make sure that healing is from the base upwards. The fistula track is then washed out with fluid and lined with gauze soaked in lotion and anaesthetic gel.
Some discharge will occur until healing is complete. A small pant liner or pad will protect your underwear if necessary. You may find that using a barrier cream on the skin around the wound edges helps to protect the skin. If hairs start to grow you may need to have these shaved to prevent them from growing into the wound. You should take a bath or use a bidet to clean the area after opening your bowels.
What should I do if I bleed after I go home?
You are quite likely to have a small amount of bleeding from the wound or the anus after the operation. You may notice this particularly after your dressing has been done, or on your stool or on the toilet paper when you wipe yourself. This is normal and nothing to worry about. You may also have a discharge from the wound for some weeks. It is a good idea to wear a small pad inside your pants to protect your clothes from any staining. In the unlikely event that you should have more major bleeding, you should contact the A&E or your own doctor.
How long should I stay off work?
The time taken to get back to normal activities varies for different people and with the extent of your surgery. Do as much as you feel comfortable doing. If you need to take painkillers these may make you drowsy, so you should avoid driving or operating machinery. If lifting causes you discomfort you should avoid it. Most people need a week or two off work once they go home, but this will depend on what you do and the extent of your fistula.
It is advisable to avoid sitting still or walking for long periods at first. You should not go swimming until your wound has healed as the chlorine in the water may affect wound healing and there is a chance of picking up or passing on an infection. You may find that vigorous exercise is uncomfortable. Start with gentle walking and build up your activity level gradually. You can resume sexual relations as soon as you feel comfortable to do so.
Are there any long-term effects of the operation?
In a very few cases if someone has weak muscles around the back passage (anal sphincter) and a tendency to difficulty in controlling the bowels, or leakage, this may worsen after the operation. If you find that you are having difficulties talk to your doctor.
What should I do if I want further information?
If you have a problem, or any questions immediately after you go home please call the ward where you were an inpatient. If a problem occurs a few days after you go home, please contact your own family doctor or district nurse for advice.
Some of the information in this leaflet has been adapted with kind permission from St Marks Hospital, Watford Road, Harrow, Middlesex.