Sphincterotomy

What is a sphincterotomy?

A lateral internal sphincterotomy, often just called a sphincterotomy, is an operation to treat an anal fissure. An anal fissure is a tear in the lining of your anus (back passage), and this operation cuts part of the muscle around it to help the tear heal.

What conditions does a sphincterotomy treat?

This operation is used for chronic anal fissures, meaning a tear that hasn't healed within 8 to 12 weeks despite other treatments. It's considered when you have ongoing severe pain during bowel movements that affects your quality of life, or when the muscle around the fissure keeps going into spasm.

What are the benefits of a sphincterotomy?

A sphincterotomy is very effective, with around 19 in 20 people having their symptoms fully resolve. Most of the fissures treated this way are completely healed within 2 to 4 weeks.

What happens before a sphincterotomy?

Before a sphincterotomy is considered, you'll usually have tried other treatments first, such as a nitroglycerin ointment or a calcium channel blocker cream. Some people also have a Botox injection into the muscle as a step before surgery.

Surgery is usually considered once a fissure has lasted more than 8 to 12 weeks despite these treatments, or if you have severe pain that's affecting your quality of life.

On the day of your operation, you'll need to fast, from midnight the night before for a morning operation, or from 7am for an afternoon operation. You won't usually need any special bowel preparation, though you may be given an enema an hour or so beforehand unless your pain is severe.

What happens during a sphincterotomy?

A sphincterotomy is usually a quick, day-case operation. It follows a similar pattern each time:

1. You're given a general anaesthetic, so you'll be asleep and feel no pain
2. Your surgeon makes one small cut in part of your internal anal sphincter muscle, the ring of muscle that helps control your bowel movements
3. This releases tension in the muscle, which improves blood supply to the fissure and helps it heal
4. Before you leave the operating theatre, you're given an injection of local anaesthetic to keep the area pain-free for around 6 hours afterwards.

The whole operation takes about 15 minutes.

What does recovery from a sphincterotomy look like?

You'll usually be able to go home the same day, once you've recovered from the anaesthetic, though occasionally you may need to stay longer. You won't be able to drive yourself home, so you'll need to arrange for someone to collect you.

You're likely to have some pain once the local anaesthetic wears off, though this is usually less than the pain of the fissure itself, and it should settle within about 4 weeks. It helps to keep your stools soft, so eat plenty of fibre and drink 6–8 glasses of water a day.

You'll be given pain relief and laxatives to take home, and laxatives may need to continue for up to 4 weeks. Some minor bleeding is normal, so wearing a sanitary towel changed twice a day, and washing the area with water twice a day and after every bowel movement, can help.

Most people return to work and normal activities, including driving, within 1–2 weeks, though your surgeon will confirm when it's safe for you to drive. Most fissures are fully healed within 2–4 weeks, and you'll have a follow-up appointment 1–2 weeks after your operation to check how the wound is healing.

What are the risks and complications of a sphincterotomy?

Cutting the sphincter muscle means a small part of it is permanently lost. This has no effect on most people, but around 1 in 20 people have minor faecal incontinence afterwards, such as slight soiling in your underwear; for some this improves over time, but for others it's permanent. Because of this risk, the operation is usually offered mainly to men with strong sphincter muscles, and is only occasionally considered for women.

As with any operation, there's also a small risk of bleeding, infection, or a reaction to the anaesthetic, though these are rare. Short-term problems, such as ongoing discomfort while you heal, are more common, affecting up to half of people, but these usually settle as you recover.