You can get an anal fistula as a result of an infection or a collection of pus (abscess) in or around your anus. It can also be caused by conditions that affect your bowel, such as Crohn's disease.
There are different types of fistula. Some develop as a single tunnel running from your rectum to your skin. Others may be more complex and 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 coming back. Symptoms of an anal fistula can include:
These symptoms aren't always caused by an anal fistula but if you have them, see your doctor.
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 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 insert a tiny probe that will go through the fistula to find its path. This may be carried out under general anaesthesia. This means you will be asleep during the procedure. If the fistula is not too deep and simple, it may be treated at this time.
Surgery is the main treatment for anal fistulas.
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 an enema an hour or so before your operation to empty your lower bowel before surgery.
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 regional 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 will usually be able to go home the same day after having anal fistula repair.
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 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.
The exact operation you have will depend on the type of fistula you have - your surgeon will examine your fistula and decide the best way to treat it.
If your fistula is not too deep (superficial), it can be 'laid open'. This is called a fistulotomy. The fistula is opened up so that it can heal from inside out. This is the simplest and most effective way to treat a fistula. A dressing is usually worn over the fistula until it has fully healed.
If your fistula is deep or complex, it may be necessary to leave a thread of suture material in the fistula tract. This is called a seton and may need to remain in place for some time. Further surgery may be necessary to adjust the seton until your fistula has healed. For some people, the seton may be left in place permanently.
If you have a deeper fistula or more than one fistula, your surgeon may use a procedure using a mucosal advancement flap. In this technique, the surgeon removes your fistula completely (fistulectomy) and stretches flaps made of tissue from your rectum over the opening of your fistula.
Sometimes a special protein-based glue or plug is used. Glue is injected into your anal fistula. The plug is inserted into your fistula and stitched in place. The aim is to seal off your fistula where it joins your bowel while still allowing any pus to drain out as your fistula heals and new tissue grows.
A new technique for treating a complex fistula is called ligation of intersphincteric fistula track (LIFT) procedure. This involves tying your fistula off within your sphincter muscle.
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.
It's normal to have some bleeding, spotting of blood on your dressing or toilet tissue, for several days after your operation. Your nurse will apply a new dressing as necessary.
Your surgeon will give you instructions about how to look after and dress your wound. Your wound may need to be re-dressed daily until it heals. You may need to take a bath to soak off the dressing from your wound.
An appointment may be made for you by your nurse at your GP surgery or with a district nurse who will visit you at home. You will be given a letter to give to your GP or 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.
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 24 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.
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 your 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.
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 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 are when problems occur during or after the operation. Specific complications of anal fistula operation are uncommon, but can include:
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.
Produced by Kerry McKeagney, Bupa Health Information Team, June 2012.
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