Anal fistula - Symptoms of an anal fistula
NHS Choices Medical Reference
There are several common symptoms of an anal fistula.
- skin irritation around the anus (the opening where waste leaves the body)
- a throbbing, constant pain that may be worse when you sit down, move around, have a bowel movement or cough
- a discharge of pus or blood when you have a bowel movement
If your fistula was caused by an abscess that you still have, you may have:
- a high temperature of 38C (100.4F) or over
- a general feeling of being unwell
If your fistula was caused by inflammation of the intestines (part of your digestive system), for example because of a condition such as irritable bowel syndrome or ulcerative colitis, you may also have:
Read more information about the causes of an anal fistula.
Types of fistula
Anal fistulae are classified depending on their position and how close they are to the sphincter muscles. The sphincter muscles are two rings of muscles that open and close the anus. They are known as the internal and external sphincter muscles.
The most common types of anal fistula are:
Intersphincteric fistula - the fistula tract (channel) crosses the internal sphincter and then opens on the surface of the skin next to the anus.
Transsphincteric fistula - the fistula tract passes through both the internal and external sphincters and opens on the surface of the skin next to the anus.
Other types of anal fistula can:
- begin at a different part of the colon (large intestine)
- extend in a different direction, so that the fistula does not open next to the anus
- develop in a horseshoe shape, with two open ends either side of the anus