An anal fissure (tear) causes pain in the anus. The pain is worse when you pass faeces (stools or motions). A fissure heals within 1-2 weeks in most people, but lasts longer in some. Treatment aims to ease the pain until the fissure heals, and to keep the faeces soft and easy to pass. An anal fissure that lasts more than six weeks is called a chronic (persistent) anal fissure. Treatment options for a chronic anal fissure include an ointment to relax the anal muscle, and surgery. These treatments reduce the tone (pressure) around the anus, which allows better healing of the fissure.
An anal fissure is a small tear of the skin of the anus. Although the tear of an anal fissure is usually small (usually less than a centimetre), it can be very painful because the anus is very sensitive. The pain tends to be worse when you pass faeces (sometimes called stools or motions) and for an hour or so after passing faeces. Often an anal fissure will bleed a little. You may notice blood after you pass faeces. The blood is usually bright red, and stains the toilet tissue, but soon stops.
Anal fissures are common in both adults and children. They are not usually serious, but they are sore and can be distressing, particularly for children.
In most people the fissure heals within 1-2 weeks or so, just like any other small cut of the skin. Some fissures take longer to heal. A fissure that lasts more than six weeks is called a chronic anal fissure (chronic means persistent.) This is uncommon, but treatment can still be effective.
Most anal fissures are thought to be due to passing large or hard faeces when you are constipated. The rim of the anus may stretch and tear slightly. Spasm (tightening) of the muscle around the anus (the sphincter) may play a part in causing the tear, or in slowing down the healing process.
In about 1 in 10 cases, the fissure occurs during childbirth. Sometimes an anal fissure occurs if you have bad diarrhoea.
In a minority of cases, a fissure occurs as part of another condition. For example, as a complication of Crohn's disease or an anal herpes infection. In these situations you will have other symptoms and problems as well. These type of fissures are not dealt with further in this leaflet.
It is thought that the muscle tone (pressure) around the anus is quite high in people with a chronic anal fissure. If the muscle tone around the anus is high, the blood supply to the anus is reduced. This can affect how well the tear heals.
Doctors and patients can use Decision Aids together to help choose the best course of action to take.Compare the options for Anal Fissure.
In most people the fissure heals within a week or so, just like any other small cut or tear to the skin. Treatment aims to ease the pain and to keep the faeces soft whilst the fissure heals.
There are separate leaflets called 'Constipation in Adults', 'Constipation in Children' and 'Fibre and Fibre Supplements' that provide more details about fibre and constipation.
The above measures apply to children who have a fissure as much as to adults. In children, the pain often makes them hold on to their faeces. This may lead to a vicious circle, as then even larger and harder faeces form, which cause more pain when they are finally passed. Therefore, in addition to the above measures, a short course of laxatives may be prescribed for children with an anal fissure. The aim is to make sure their faeces are soft and loose whilst the fissure heals.
An anal fissure will heal within 1-2 weeks in most people, but takes longer to heal in some people. Even if it has lasted six weeks, when it technically becomes a chronic anal fissure, there is still a reasonable chance that it will heal on its own without treatment. However, treatment can help to heal the fissure as quickly as possible.
Treatment aims to:
If you apply glyceryl trinitrate (GTN) ointment to the anus, it relaxes the muscle around the anus (the anal sphincter). This may allow the fissure to heal better. It may also ease the pain very quickly. A doctor may advise that you use GTN if you have had an anal fissure for longer than a week or so, and particularly if you have a chronic anal fissure.
GTN may help in some, but not all, cases. Research studies have shown that, for people with a chronic anal fissure, about 6 in 10 fissures healed with GTN treatment. This compared to about 5 in 10 that healed with no treatment. So, the effect of GTN is modest, but may well be worth a try.
Some points to note if you use GTN ointment include the following.
An operation is an option if the fissure fails to heal despite the above treatments. It is also an option if you have recurring fissures. The usual operation is to make a small cut in the muscle around the anus (internal sphincterotomy). This permanently reduces the tone (pressure) around the anus and allows the fissure to heal. This is a minor operation which is usually done as a day case under general anaesthetic.
The success rate with surgery is very high - at least 9 in 10 cases are cured.
As with any operation, there is a risk of complications. After this operation, some people have poor control of gas (wind), and a very small number have soiling of underclothes, or mild bowel incontinence. But, studies have demonstrated that the risk of these complications is small, and the vast majority of people who have this operation are pleased with the result to be free from the symptoms of an anal fissure. And for some, to be free of the problem of recurring anal fissure.
Some studies suggest that other medicines may be useful to relax the anal sphincter muscle and quicken healing. For example, drugs called calcium antagonists have been studied and seem to have some effect. Also, injections of botulism toxin into the anal sphincter muscle have been studied to see if this relaxes the muscle. Further studies are needed to clarify the role of these newer treatments.
Some people seem prone to recurring anal fissures. Up to half of people who have a chronic anal fissure successfully treated with GTN ointment will have one or more recurrences at some time in the future. It is thought that these people have an ongoing higher than average pressure (tone) of the muscle around the anus. They are more likely to tear the rim of the anus if it is stretched. However, a further course of GTN ointment can be used to help to heal any future fissure. Surgery may be an option if you have frequent recurrences.
If you have had one anal fissure, after it has healed you have a higher than average chance of having another one at some time in the future. The best way to avoid a further fissure is not to become constipated by using the measures described above. That is, a high-fibre diet, fluid, etc. Leaflets that list foods high in fibre are commonly available. Ask your practice nurse for one if you cannot obtain one.