Anal fissure procedures

Expert reviewer, Mrs Sara Badvie, Consultant Laparoscopic, Colorectal and General Surgeon
Next review due September 2021

If you have an anal fissure that hasn’t healed with self-help measures and medical treatments, your doctor may suggest a procedure to treat it. 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 procedures available, including injections with botulinum toxin, removal of the fissure (excision or fissurectomy) and sphincterotomy. Your doctor will discuss with you which one is right for you.

An image showing an anal fissure

About treatments for anal fissure

Anal fissures are often associated with having hard, painful bowel movements. They’re thought to develop when muscles around your anus, called sphincter muscles, spasm and tense up. This reduces the blood supply to the area, which stops the tear from healing properly. Having further hard bowel movements can then make the fissure come back, or get worse.

Anal fissures often go away by themselves with a few self-help measures such as increasing your fibre and fluid intake to soften your stools, and taking warm baths. Your doctor may also prescribe you an ointment or cream. See our Anal fissure topic for more information on these treatment options.

If these measures don’t help your anal fissure, your doctor may suggest that you have a procedure to treat it. There are different types of procedure for anal fissures. The main ones are covered in the sections below.

Botulinum toxin injections

What are botulinum toxin injections (Botox) for anal fissure?

An injection with botulinum toxin (Botox) is a procedure that’s carried out in an operating theatre at a hospital. Your surgeon will usually suggest you try this before other surgical procedures. You’ll usually have it under general anaesthesia, which means you’ll be asleep during the procedure. Once the anaesthetic has taken effect, your surgeon will apply the injection directly into your internal sphincter muscle. The aim is to temporarily relax this muscle so that your fissure can heal.

How well does it work?

Around seven in 10 people find that their fissure heals after a Botox injection. Some people need a second set of injections, three to four months after the first one, in order for the fissure to heal completely. It’s possible for a fissure to return after Botox injections, sometimes years later.

What are the risks?

There can be some side-effects of Botox injections. Around one in 10 people find they have some problems controlling wind at first. And less commonly, some people have problems controlling bowel movements (incontinence). These problems will only last until the effects of the Botox injection wear off – usually after around three months.

Very rarely, Botox can spread to other parts of your body, causing weakness in your muscles and difficulties with breathing. Talk to the healthcare team at the hospital if you experience any of these symptoms after the procedure.


Your surgeon may sometimes suggest you have a procedure called a fissurectomy alongside Botox injections. This involves cutting away the damaged skin from around your anal fissure, along with any ‘sentinel’ skin tags (lumps of skin associated with the fissure).

Lateral internal sphincterotomy

What is a sphincterotomy?

This is a type of surgery that involves cutting the sphincter muscles around your anus, to release the tension and let your fissure heal. Your doctor will usually only suggest this after you’ve tried other treatments first, including Botox.

You’ll usually have this procedure under general anaesthesia, which means you’ll be asleep during the operation. The procedure can be done in two ways. In an open sphincterotomy, your surgeon will make a small cut in your skin to reach the sphincter muscle. They will then be able to see the muscle directly as they cut into it. The cut in your skin will usually be left open to heal. In a closed sphincterotomy, your surgeon will pass a blade under your skin to reach and cut the muscle.

How well does it work?

Sphincterotomy is very effective – around 95 in 100 people find that their fissure heals after having this surgery.

What are the risks?

Although sphincterotomy is much more effective than other treatments for anal fissure, incontinence is a more common complication after this procedure. Up to 3 in 10 people may have some problems with controlling their bowel movements. Most often, these are minor, temporary problems, such as having trouble controlling wind or minor soiling, which ease off over time. However, it’s possible to have permanent problems involving some loss of control.

There is a small risk of developing an infection after sphincterotomy – around one or two in every 100 people are affected. 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 when you have a bowel movement. An infection can usually be treated by draining the abscess or sometimes, taking antibiotics.

It’s also possible to develop something called an anal fistula. This is a small channel between your back passage and your skin. Less than one in 100 people who have a sphincterotomy develop this. The fistula is usually very small and can be treated with surgery.

Anal advancement flaps

Anal advancement flaps involves taking healthy skin from your anal lining and using it to replace the broken skin in your fissure. The healthy skin will be attached into place with stitches. This procedure is not carried out very often. You may have it at the same time as a sphincterotomy or afterwards if your fissure still doesn’t heal. It may also be an option if you’re at greater risk of developing incontinence after surgery.

Deciding on treatment

When you first meet with your doctor about your anal fissure, they will run through any possible treatment options with you and make sure you understand what’s involved. If they’re recommending a certain procedure, they will discuss what will happen before, during and afterwards, and any possible complications you might have.

This is your opportunity to ask questions so that you understand what will be happening. You can go away and think about it you don’t have to go ahead with a procedure if you decide you don’t want it. You may prefer to carry on trying further treatment with creams and ointments. If you do decide to go ahead with a procedure, you’ll be asked to sign a consent form (sometimes called an agreement form).

You’ll be given information and any instructions you need to follow, such as when to stop eating and drinking before the procedure and what will happen on the day.

What to expect after an anal fissure procedure

Anal fissure procedures are usually done as a day-case procedure in a hospital. This means you have the procedure and go home on the same day. You’ll 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 should be able to go home as soon as you feel ready. You’ll need to arrange for someone to drive you home, as you shouldn’t drive after a general anaesthetic.

A general anaesthetic can affect your co-ordination and make it difficult to think clearly. As well as not driving, you shouldn’t drink alcohol, operate machinery or sign anything important. Most hospitals will only discharge you on the day of your procedure if there’s another adult at home. So you’ll need to make plans beforehand to have a friend or relative stay with you for the first 24 hours.

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 that your wound and fissure are healing properly.

Recovering from anal fissure procedures

You will usually be prescribed painkillers and laxatives (to prevent constipation) after the surgery. You can change to simple paracetamol or ibuprofen as soon as you feel ready. 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 breads and cereals. Your doctor may also suggest that you take fibre supplements. If you’ve had a sphincterotomy, your wound may be left open to heal naturally. Keep the area clean and dry to help it to heal and avoid developing an infection.

The recovery time varies from person to person, although most people feel well enough to return to their usual activities within a few days.

Frequently asked questions

  • You should be prepared for some pain and discomfort in your anus after anal fissure surgery. The pain is usually worst during the first seven days after surgery, and will get significantly better after this first week. It will help you to be more comfortable if your stools are soft. Drink plenty of fluids and eat a high-fibre diet containing lots of fruit and vegetables and wholegrain foods. Make sure you take any laxative that your surgeon has prescribed too. This will help to make your stools softer.

    It’s important to keep your anal area clean and dry too. You may want to have a bath or shower after every bowel movement, in the first few days. Then you can clean the area with damp cotton wool. You might notice blood on the toilet paper after you’ve had a bowel movement for up to 10 days after your operation.

  • If your anal fissure doesn’t heal, or comes back after a sphincterotomy, your surgeon may suggest you have some tests to check whether the surgery went to plan. These may include an ultrasound scan of your anus and tests to see how well your sphincter muscle is working. Your doctor may also suggest tests to check there’s no underlying cause. Some people with recurrent fissures have an underlying medical condition, such as Crohn’s disease or a sexually transmitted infection, that could be causing the fissure. Your fissure may heal if any underlying conditions are treated.

    If this has been ruled out, your doctor may suggest trying the same treatment again, or another type of treatment, depending on your individual situation.

  • You will usually be advised against having an anal sphincterotomy if you’re a woman and still plan to have children, or if you’ve previously had a complicated childbirth. This is because injuries you may get during a complicated childbirth can put you at greater risk of developing incontinence following a sphincterotomy.

    You’ll usually be offered botulinum toxin (Botox) injections as a first option if self-help and medical treatments haven’t worked. Anal advancement flaps can also be another option for women who are at greater risk of developing incontinence. 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 isn’t as likely to cause problems with bowel control afterwards.

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  • Reviewed by Pippa Coulter, Freelance Health Editor, September 2018
    Expert reviewer Mrs Sara Badvie, Consultant Laparoscopic, Colorectal and General Surgeon
    Next review due September 2021