Rectal Fistula

Author: Marisa Healy, BSN, RN
Content Contributor: Katherine Okonak, LSW
Last Reviewed: August 02, 2024

What is a rectal fistula?

The rectum is the last part of the large intestine. It is a muscular tube about 5 inches long. The anus is the opening at the very end of the intestines, right after the rectum, where stool (bowel movements) exits the body.

A rectal fistula is a small tunnel or opening between the rectum and a nearby structure, like a gland or the urethra (the tube that carries urine from the bladder to outside of the body). A rectal fistula that is caused by cancer treatment most often involves the rectum and urethra. It is a very rare problem.

Symptoms of a rectal fistula are:

  • Abscesses (swollen, infected areas filled with pus) that keep coming back (recurrent). 
  • Pain and swelling around the anus.
  • Pain and/or bleeding with bowel movements.
  • Bloody or foul-smelling drainage from around the anus.

A rectal fistula is a medical emergency. If you have any of the symptoms above, call your care provider right away. Your provider may look at the area around the anus and if it can be seen, the fistula can be diagnosed. If the fistula is not easily seen, you may need more tests. These tests may include an anoscopy, a test where your provider uses a tool to see inside your rectum.  An MRI may also be used.

How is a rectal fistula treated?

Rectal fistulas are treated with surgery done by a colon and rectal specialist. It may be done as an outpatient procedure, or you may need to stay in the hospital for a few days.

When should I call my care team?

If you have any of the symptoms of a rectal fistula listed above, call your care team right away.