Anal stenosis

Symptoms

The restriction of the anal canal prevents the normal expulsion of faeces, resulting in difficulty and pain when trying to open the bowels, and leading to constipation. Babies may also experience pain when trying to open their bowels.

Causes and risk factors

Anal stenosis may be present from birth, when it might be accompanied by malformations of the anal opening. This happens in one in several thousand births.

Sometimes the opening appears further forward than normal. In girls, it's usually immediately behind or inside the female genitalia. In boys, there may be no obvious opening at all or just a small area of bulging skin or a tiny channel under the skin.

More commonly, stenosis develops as a result of scarring from a tiny fissure, or crack, in the anal canal. This is usually the reason why adults develop anal stenosis, but it can also occur in babies.

Anal stenosis may also develop after surgery to the anus, for example after the removal of piles or haemorrhoidectomy.

Treatment and recovery

Low-risk treatments:

Laxatives, suppositories and other treatments are used to help loosen motions and lubricate the anal canal, to make it easier to empty the bowels. There's little risk the person affected will come to any harm from these treatments if they're used as prescribed and only for a matter of months while the problem settles. (It must be remembered that the risks are considerably less than those that might occur if the affected person becomes very constipated).

Individuals suffering from anal stenosis aren't likely to become dependent on the laxatives and suppositories.

However, its also important to make dietary changes (such as plenty of raw fruit and vegetables to provide natural fibre, and plenty of fluid to avoid dehydration) in order to keep the motions soft. Regular exercise also helps keep a regular bowel habit.

Surgical treatments:

In mild cases, gentle and gradual dilation by the regular passage of normal motions may be enough. But quite often surgery is needed, especially in more severe cases. The surgical treatment of anal stenosis depends on the extent of the problem. In most cases all that's needed is for the anal canal to be stretched. Often this can be done by the doctor in the hospital clinic, without the need for anaesthetic.

If the stenosis is severe, dilation may performed under anaesthesia. More major surgery is only needed if the anal canal needs reconstructing or (in small children with congenital anal stenosis) it needs repositioning or there are other malformations that require surgery.