An anal fissure is a tear or open sore (ulcer) that develops in the lining of the anal canal. It's found between the rectum – where stools (poo) are stored – and the opening in the bottom stools are passed through (anus). See your GP if you think are concerned.
Anal fissure symptoms
The most common symptoms of anal fissures are:
- a sharp pain when you pass stools, often followed by a deep burning pain that may last several hours
- bleeding when you pass stools – most people notice a small amount of bright red blood either in their stools or on the toilet paper
When to see your GP
See your GP if you think you have an anal fissure.
Most anal fissures get better without treatment. But your GP will want to rule out other conditions with similar symptoms, such as piles (haemorrhoids).
Your GP can also tell you about self-help measures and treatments.
Diagnosing anal fissures
Your GP will ask you about your symptoms and the type of pain you've been experiencing. They may also ask about your toilet habits. They'll usually be able to see the fissure by looking at the area.
Your GP may refer you for specialist assessment if they think something serious may be causing your fissure.
Causes of anal fissures
Many anal fissures have no identified cause. Anal fissures are commonly caused by damage to the lining of the anus or anal canal.
Cases occur in people who have constipation, when a particularly hard or large stool tears the lining of the anal canal.
Other possible causes of anal fissures include:
- persistent diarrhoea
- inflammatory bowel disease (IBD), such as Crohn's disease and ulcerative colitis
- pregnancy and childbirth - due to pressure on the perineum
- occasionally, a sexually transmitted infection (STI), such as syphilis or herpes, which can infect and damage the anal canal
- cancer of the colon or rectum
- skin conditions, such as psoriasis and pruritus ani
- bacterial, fungal, or viral skin infections
- anal trauma, for example from previous anal surgery or anal sex
- some prescribed medications can cause it (check with your pharmacist or GP) as can chemotherapy treatment
- having unusually tight anal sphincter muscles, which can increase the tension in your anal canal, making it more susceptible to tearing
People commonly affected by anal fissures
Anal fissures are quite common, with an estimated one in every 350 people are affected.
They are more common in people aged 15–40 years. But they can occur at any age, including in young children (due to poor anal hygiene).
They are common in pregnant and women who have recently had a baby. Anal fissures are the second most common gastrointestinal complication of pregnancy (the first being haemorrhoids).
Anal fissures without an identified cause are uncommon in elderly people.
Treating and preventing anal fissures
Anal fissures usually heal within a few weeks without the need for treatment. They can easily happen again if they're caused by constipation that is not treated.
In some people, symptoms from anal fissures last six weeks or more.
Adopting some simple self-help measures can make passing stools easier. This will allow existing fissures to heal. It can also help to reduce your chances of developing new fissures in the future.
Self-help measures for avoiding constipation include:
- plenty of fibre in your diet, such as fruit and vegetables and wholemeal bread, pasta and rice – adults should aim to eat at least 18g of fibre a day
- staying well hydrated by drinking plenty of fluids
- not ignoring the urge to pass stools – this can cause your stools to dry out and become harder to pass
- exercising regularly – you should aim to do at least 150 minutes of physical activity every week
You can help soothe the pain by:
- by soaking your bottom in a warm bath several times a day, particularly after a bowel movement
Your GP can also prescribe medication to help relieve your symptoms and speed up the healing process.
This can include:
- laxatives to help you pass stools more easily
- painkilling ointment that you apply directly to your anus
Surgery may be recommended in persistent cases of anal fissure where self-help measures and medication haven't helped.
More useful links
The information on this page has been adapted from original content from the NHS website.
For further information see terms and conditions.