Anal Fissure

A fissure is a crack in the anal skin. It usually causes pain and bleeding when the bowels work. It often heals on its own. If not, there are several effective treatments.

How does a fissure happen?

It is usually caused by a bowel motion which is large or hard. Occasionally it follows diarrhoea. It results in spasm of the anal muscle, that prevents the fissure to heal. Many fissures heal with no specific treatment. In some people, the fissure recurs from time to time. In others it does not heal at all. If a fissure has come and gone for months, a lump of swollen skin (called a skin tag) can form next to it. It can be felt at the anus. Less often, a lump forms at the inner end of the fissure, inside the anus. It is called an anal polyp. It sometimes hangs out after a bowel action, causing pain.

How is a fissure diagnosed?

The anus is inspected gently with a strong light. This should not hurt. In most patients, this is enough to confirm the diagnosis. Occasionally the anus is so sore that this is impossible. Then an examination under anaesthetic is needed, to confirm the diagnosis and to treat the problem at the same time.

In a few cases, it is necessary to rule out other causes for the symptoms. This needs more than simply inspecting the anus. Wiping local anaesthetic jelly on the anal skin usually makes it possible to feel inside the anus with a finger, without pain. Sometimes the problem can be seen more clearly by passing a lighted tube into the anus. These examinations are only done if they are not painful. They are uncomfortable for the patient, but they should not hurt. If the examination starts to cause pain, it is stopped at once.

How is a fissure treated?

The alternatives are to let it heal on its own, to use medication, or to have an operation called a sphincterotomy.

If a fissure has only been present for a week or two, it usually heals in a few days. Treatment aims to relieve the pain (by applying local anaesthetic jelly before a bowel motion) and by keeping the motions soft (laxatives like Fybogel, Movicol or Normacol work best).

If the fissure does not heal, we treat it with medications to relax the anal muscle. Nitrate cream together with stool softeners and local anaesthetic jelly is used. If the cream does not heal the fissure, we use BOTOX injection to relax the muscle for a longer period. Medical treatment does not affect the control of the bowels. These treatments are effective, but the fissure can sometimes persist or recur. If a fissure persist despite the optimum treatment, surgery can be done to permanently relax part of the anal muscle (sphincterotomy). There is a small chance that a sphincterotomy can reduce the control over winds and loose stools and one should not undergo this procedure if you are unwilling to accept this.