An anal fissure is a tear in the delicate lining of the anus. It's a relatively common problem and is most often caused by passing a hard, dry stool. Diarrhoea and any inflammation in the area can also cause a tear.

With an anal fissure, passing bowel motions can be very uncomfortable. Bright red fresh blood will often appear in the toilet bowl or on toilet tissue, which gives people a real fright. The pain then eases until the next time you open your bowels.

How it's treated

For the pain, an anaesthetic cream or gel (available from the pharmacist) works well.

Taking a sitz bath (hip bath) is also recommended if you have the time. This involves sitting in a bath of warm water that covers the hips and buttocks a few times a day.

To protect the fissure from clothes rubbing against it, use a barrier cream such as zinc and castor oil.

Eating plenty of fibre from fruit, vegetables, wholemeal bread, breakfast cereals, dried figs and prunes, and drinking at least eight glasses of water a day, will keep bowel motions soft so further damage doesn't occur. Stool-softening liquids are also available from the pharmacist.

A prescribed cream containing glyceryl trinitrate (GTN) - a drug more commonly used to treat angina - is helpful when natural scarring and spasm prevent the fissure from healing properly.

If all these treatments fail, a simple operation will be needed to remove the fissure.

This article was last medically reviewed by Dr Trisha Macnair in October 2007