Anal fistula

An anal fistula describes a small channel which forms between the end of your bowel (the anal canal) and the skin near your anus. The anus is the outward opening through which faeces are eliminated from your body. 

The end of the fistula may appear to look like a hole in the skin around your anus. It can cause bleeding and discharge while passing stools, which can cause pain and discomfort.  Anal fistulas can be classified as:

• Simple or complex – this is based on whether you have one fistula tract, or a number of interlinking connections, or

• Low or high – this depends on the position of the fistula and how near it is to your sphincter muscle (the rings of muscle which open and close the anus).

​An anal fistula is most often due to an anal abscess, which is a painful collection of pus which usually develops following the infection of a gland inside the anus. After an anal abscess bursts, and if the infected fluid has not been entirely drained, it often causes an anal fistula. 

The only real cure for anal fistula is surgical intervention. The Section of Gastroenterology at The Aga Khan University Hospital are equipped to assist you with any symptoms that you may be experiencing, whether it be related to an anal fistula or any other problem.

When to seek expert advise

​You should visit your doctor if you notice any symptoms of an anal fistula, or that worry you.​