Anal fissure surgery

Expert reviewer, Mr Stephen Pollard MA, MS, FRCS, BSc, Consultant Surgeon
Next review due March 2019

If you have an anal fissure that hasn’t healed with other treatments, your doctor may suggest surgery. An anal fissure is a small tear or ulcer (open sore) in your skin around the opening of your anus. There are several different types of surgery – your doctor will discuss with you which one is right for you.

An image showing an anal fissure

About anal fissure surgery

An anal fissure is often caused by a hard or painful bowel movement, which damages the surrounding skin. A fissure can cause a severe or burning pain in or around your anus, especially when you open your bowels. This pain can last for a couple of hours. You may also notice bright red blood on the toilet paper when you wipe yourself after a bowel movement.

The opening and closing of your anus is controlled by your internal (inside) and external (outside) anal sphincter muscles. You can control your external anal sphincter yourself, but not your internal anal sphincter. If your internal anal sphincter goes into spasm (tenses), this reduces the blood supply to your fissure and stops it healing properly.

An anal fissure can be treated with diltiazem cream or botulinum A injections. These treatments relax your sphincter muscle, allowing the fissure to heal. If these treatments don’t work, you may need surgery to relax your sphincter muscle or to remove the damaged skin.

Preparing for anal fissure surgery

Anal fissure surgery is usually done as a day-case procedure in a hospital. This means you have the procedure and go home on the same day.

Your surgeon will explain how to prepare for your operation. If you smoke, for example, you’ll be asked to stop. Smoking increases your risk of getting an infection after surgery, which can slow down your recovery. It can also make your surgery less effective and lead to complications. 

You’ll usually have anal fissure surgery under general anaesthesia. If you have a general anaesthetic, you’ll be asleep during the operation. Sometimes, you may have the surgery under spinal anaesthesia instead. Spinal anaesthesia completely stops you feeling pain below your waist, but you’ll stay awake. Your surgeon may offer you a sedative with the spinal anaesthetic. This relieves anxiety, makes you feel sleepy and helps you relax during the operation.

You’ll be asked to follow fasting instructions. This means not eating or drinking, usually for about six hours, before your surgery. It’s important to follow your anaesthetist’s advice. 

You may be asked to wear compression stockings to help prevent blood clots forming in the veins in your legs. You may need to have an injection of an anticlotting medicine called heparin as well as, or instead of, wearing compression stockings.

Your nurse or surgeon will discuss with you what will happen before, during and after your procedure, including any pain you might have. If you’re unsure about anything, don’t be afraid to ask. No question is too small. It’s important that you feel fully informed so you feel happy to give your consent for the procedure to go ahead. You will be asked to do this by signing a consent form.

What are the alternatives to anal fissure surgery?

Your surgeon will usually only recommend anal fissure surgery after you’ve tried other treatments, or if these treatments aren’t suitable for you.

Botulinum A toxin injections are usually used when medicines such as diltiazem cream haven’t worked. They relax your internal sphincter muscle to help healing. The injections may last for around three months. They may cause some side-effects, such as muscle weakness, but this should be temporary. Around one in every two anal fissures come back within a year after the injections.

What happens during anal fissure surgery?

An anal fissure can be treated with several different types of surgery. Your surgeon will explain which one is right for you. If your anal fissure doesn’t heal after surgery, your surgeon may suggest that you have the surgery again or try a different procedure.

Lateral internal sphincterotomy

This is the most common procedure for anal fissures. Your surgeon makes a small cut in your internal anal sphincter muscle to relax it. Anal fissures heal in 95 in every 100 people who have this procedure. This surgery isn’t always suitable for women of childbearing age or people with chronic (long-term) diarrhoea. 


Your surgeon may suggest a fissurectomy if they think you’re likely to develop incontinence after a sphincterotomy. This may be for several reasons, including if you have diabetes or irritable bowel syndrome. During a fissurectomy, your surgeon will remove all of the damaged skin around your anal fissure. They will then leave your fissure to heal on its own.

Advancement flaps

If you have an advancement flap, your surgeon replaces the broken skin in your fissure with a section of healthy skin from your anal lining. You may have this procedure at the same time as a sphincterotomy or afterwards if your fissure still doesn’t heal.

What to expect afterwards

Having a general or spinal anaesthetic, with or without a sedative, affects everyone differently. You may find that your co-ordination isn’t so good, or that it’s difficult to think clearly. This should pass within 24 hours. In the meantime, don’t drive, drink alcohol, operate machinery or sign anything important. Always follow your surgeon’s advice. 

You may need to rest until the effects of the anaesthetic have worn off. You may also need some pain relief to help ease any discomfort. You’ll usually be able to go home when you feel ready but you’ll need to arrange for someone to drive you home. Try to have a friend or relative stay with you for the first 24 hours. You can usually return to your normal activities on the following day.

Your nurse will give you some advice about caring for your healing wounds before you go home. You may be given a date for a follow-up appointment to check your wound and fissure are healing properly.

Recovering from anal fissure surgery

After surgery, you may find that your fissure is less painful than before your operation. If you need pain relief, you should be able to take over-the-counter painkillers such as paracetamol or ibuprofen. But check with your doctor or pharmacist first. You shouldn’t take painkillers containing codeine, as these can cause constipation. Always read the patient information that comes with your medicine.

Your surgeon will usually prescribe laxatives after the surgery to prevent constipation. They may also suggest that you take fibre supplements. You should drink plenty of fluids and eat a high-fibre diet to stop the anal fissure coming back. High-fibre foods include fruit and vegetables and wholegrain cereals. Your wound may be left open to heal naturally. Washing it gently with soap and water after every bowel movement should help it to heal within 14 days without scarring.

The recovery time varies from person to person, so it's important to follow your surgeon's advice.

What are the side-effects?

After your surgery, you may have some side-effects, which should be mostly temporary. If you experience any side-effects, it’s important to discuss these with your surgeon. 

Anal fissure surgery doesn’t usually cause much pain afterwards. Your fissure may feel sore for a while, but this should settle down once the wound has healed, usually within 14 days.

You may have some bruising around the wound, but this doesn’t usually need to be treated.

What are the complications?

Complications are when problems occur during or after a procedure.

You may develop an infection. If you have an infection, you may have a small abscess on or near your wound. This can make it painful to sit down or open your bowels. This affects only around two in every 100 people after anal fissure surgery. An infection can usually be treated by draining the abscess or sometimes taking antibiotics. 

Around one in 100 people develop an anal fistula after anal fissure surgery. An anal fistula is a small channel between your anal canal and your skin, usually caused by an abscess that doesn’t heal properly. The fistula is usually very small and can be treated with surgery.

After anal fissure surgery, you may find it difficult to control your bowel movements, which can lead to incontinence. This affects less than five in 100 people. It’s most likely to happen if you have a sphincterotomy. It may happen if your sphincter muscles were damaged or overstretched during the procedure. You’re most likely to have trouble controlling wind, but may also notice mucus or liquid stools soiling your underwear.

Up to six in every 100 people find that their fissure comes back after surgery. If your fissure comes back, your doctor may try medical treatments or suggest that you have further surgery. You may also need to have more tests. You’re more likely to have another fissure if you have an undiagnosed medical condition such as Crohn’s disease.

Frequently asked questions

  • Yes, you may feel sore for a few days or more after anal fissure surgery.

    After anal fissure surgery, your anus will feel sore, especially when you go to the toilet. If you need pain relief, you should be able to take over-the-counter painkillers such as paracetamol and ibuprofen. You shouldn’t take any medicines that contain codeine because they can cause constipation. Always read the patient information that comes with your medicine and ask your pharmacist for advice if you’ve any questions.

    You’ll need to carefully wash and dry your wound area after having a bowel movement to reduce your risk of an infection. You may find it helpful to have a warm, shallow bath. This relaxes your sphincter muscles and makes stools easier and less painful to pass.

    You should eat a healthy diet rich in fibre and drink plenty of fluids to prevent constipation. Your doctor may prescribe laxatives to make your stools softer and easier to pass. This will help your fissure heal more quickly.

  • Your surgeon may suggest having another operation using a different technique, such as a fissurectomy or anal advancement flap. 

    A lateral internal sphincterotomy is the most commonly used procedure for anal fissures. It’s also very successful. More than 95 in 100 fissures are healed following this type of surgery.

    There is a chance that your fissure may not heal, or comes back. If this happens, your surgeon may suggest you have the same operation again or try a different procedure instead. There are two alternatives. 

    • Fissurectomy – your surgeon will remove all of the damaged skin around your anal fissure, and your fissure then heals naturally on its own.
    • Advancement flaps – the damaged tissue in and around your fissure is replaced with healthy tissue from your anal lining.

    If your anal fissure keeps coming back, you may need to have some tests to check there’s no underlying cause. Some people with recurrent fissures have a medical condition, such as Crohn’s disease, that hasn’t yet been diagnosed.

  • If you’re a woman, you shouldn’t have an anal sphincterotomy if there’s any possibility that you may get pregnant and have children. This is because the procedure may increase your risk of being unable to control your bowel movements after the birth.

    Anal fissures are more common in women than in men. Women are also at an increased risk of developing an anal fissure after giving birth. 

    Lateral internal sphincterotomy is the most common treatment for anal fissures. But it can cause problems with bowel control in up to five in 100 people who have the surgery. This may happen if the sphincter muscles are damaged or overstretched during the procedure.

    Women who have a difficult labour and delivery may develop problems with bowel control after the birth. This may be caused by a forceps delivery or episiotomy, which can damage the nerves that supply the sphincter muscle.

    A sphincterotomy is more likely to cause poor bowel control in women who have had a difficult labour and delivery. So it isn’t recommended as a treatment for women who may go on to have more children.

    The advancement flap technique may be suitable for women who shouldn’t have lateral internal sphincterotomy. If you have this procedure, your surgeon replaces the broken skin in your fissure with a section of healthy skin from your anal lining. An advancement flap isn’t as effective as a sphincterotomy, but it doesn’t cause problems with bowel control afterwards.

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  • Reviewed by Pippa Coulter, March 2016
    Expert reviewer, Mr Stephen Pollard MA, MS, FRCS, BSc, Consultant Surgeon
    Next review due March 2019

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