Anal fissure

An anal fissure is a break, tear or open sore in the lining of the anal canal.

The anal canal is the last part of the large intestine, located between the rectum and the anus, through which your stools are passed. A tear in the lining of the anal canal is called an anal fissure which can have a number of possible causes.

The most common cause of anal fissures is damage to the lining of the anal canal or anus.

Constipation can be a contributory factor - most cases of anal fissure occur when a particularly hard or large stool tears the lining of the anal canal.

Anal fissures can also be caused by:

  • recurring diarrhoea
  • inflammatory bowel disease (IBD), for example Crohn's disease and ulcerative colitis
  • pregnancy and childbirth
  • rarely, a sexually transmitted infection (STI), such as syphilis or herpes, which can damage the anal canal
  • tight anal sphincter muscles can increase tension in your anal canal, making you more prone to anal fissures.

In many cases a clear contributory cause cannot be identified.

Initially your GP will ask you about your symptoms, the pain you’re experiencing and how often you’re opening your bowels. They may be able to see the anal fissure by gently parting your buttocks.

At this point, your GP may refer you for specialist assessment if they suspect something serious is causing your fissure. This could include a more thorough examination of your anus and anal canal under anaesthetic to minimise pain.

Sometimes, a measurement of anal sphincter pressure is taken for anal fissures that haven't responded to simple treatments.

Symptoms of anal fissures include a sharp pain when stools are passed. This may be followed by a deeper, burning pain, perhaps for several hours. There may be some bleeding from the anus when stools are passed.

Anal fissures are quite common; it’s estimated that one in every ten people are affected at some stage in their life. Apart from the pain, the first symptom of anal fissures for most people is a small amount of bright red blood either in their stools or on the toilet paper. Anal fissures affect both males and females equally and they occur in people of all ages, including very young children. However, most sufferers are children and young adults between the ages of 10 and 30.

If you think you have an anal fissure, the first step is to see your GP. It’s only natural that you might feel embarrassed, but don't let that stop you seeking help. It’s a common complaint that GPs are used to dealing with. Most anal fissures get better without treatment, but it’s important that your GP rules out other conditions with similar symptoms, such as piles (haemorrhoids).

  • sharp pain when passing stools
  • a deeper, burning pain, perhaps for several hours after passing stools
  • bleeding (bright red blood) when you pass stools

Non-surgical treatment is recommended initially for anal fissures, whether acute or chronic (those lasting six weeks or more). Anal fissures typically heal within a few weeks without any treatment. However, if they're caused by constipation that remains untreated, they can recur.

A first step may be to help yourself avoid constipation. Make sure you have plenty of fibre in your diet - this is found in foods such as fruit, vegetables and wholemeal bread, rice and pasta. Try to stay well hydrated by drinking plenty of fluids. Make sure you exercise regularly and, finally, don’t ignore the urge to open your bowels as this can cause your stools to dry out and become harder to pass.

If you’re suffering from pain, you can take simple painkillers such as ibuprofen or paracetamol. A soak in a warm bath may help - do this several times a day, particularly after a bowel movement.

Your GP may also prescribe other medication to help relieve your symptoms and aid healing. For example, laxatives may help your stools to pass more easily and ointment, applied directly to your anus, may help relieve pain.

If surgery is required this could involve an anal stretch (anal dilation) or lateral sphincterotomy (a surgical procedure where the internal anal sphincter muscle is cut). These treatments mean you will strain less when going to the toilet and put less pressure on the fissure, giving it time to heal.

Surgery is usually very effective in the successful treatment of anal fissures, but there is a small risk of complications. This includes the possibility of temporary or permanent loss of bowel control (bowel incontinence).

Flexible sigmoidoscopy

A flexible sigmoidoscopy is a procedure to look inside the rectum and lower part of your bowel.


A colonoscopy is a procedure to look at the lining of the back passage (rectum) and large bowel (colon).


Lateral sphincterotomy is a surgical procedure where the internal anal sphincter muscle is cut to help relieve an anal fissure.

What next?

If you are suffering with a suspected condition, you should seek the advice of your doctor who will be able to refer you to Benenden Hospital for diagnosis and treatment.

There are four ways to access treatment at Benenden Hospital which include self-funding, using private medical insurance or your Benenden membership, or through the NHS e-Referral scheme.