An anal fissure is a common and painful condition where a tear or ulcer develops in the anal canal, that's between the rectum and anal opening.
Pain from an anal fissure is usually felt when going to the toilet to pass a bowel motion, with a burning pain lasting for some hours afterwards.
Blood may be noticed on toilet paper or in poo.
Although many people feel embarrassed about talking to a doctor about symptoms of an anal fissure, it is important to get advice on relieving symptoms, as well as ruling out other causes of the symptoms, such as piles ( haemorrhoids).
It is estimated that 1 in 10 people will experience an anal fissure during their life.
Causes of anal fissures
In some cases, the cause of an anal fissure is not known, but it often results when hard or large stools (poos) tear the anal canal lining, particularly when people have constipation.
However, persistent diarrhoea can also be a cause, as can inflammatory bowel disease, pregnancy and labour, sexually transmitted infections (STIs) or having anal sphincter muscles that are tighter than usual.
Anal fissure diagnosis
A doctor will usually diagnose an anal fissure based on the symptoms, bowel habits and a gentle examination of the fissure.
Depending on the findings, further tests or a specialist referral may be recommended.
Anal fissure treatment and prevention
An anal fissure will usually heal over some weeks without any specific treatment. Taking painkillers can help with the pain from an anal fissure, and a doctor may recommend a topical painkiller (gel) to apply to the area before going to the toilet.
Extra fibre in the diet, drinking plenty of fluids and the short-term use of laxatives may be advised to help prevent straining when going to the toilet. Avoiding constipation, and always going to the toilet when you get the urge to go, can also help prevent further anal fissures developing.
Taking exercise can also be beneficial.
If symptoms last beyond a few weeks, glyceryl trinitrate (GTN) ointment may be prescribed to help increase blood flow to the area and promote healing.
If other treatments haven't been effective, an operation may be recommended. Surgical procedures can be effective treatments for anal fissures, but there is a risk of complications, including loss of bowel control.
Anal fissure diagram