Anal fistula

Need to know

• What are the symptoms of an anal fistula? icon plus

  Symptoms of anal fistulas can range in severity, from mildly bothersome to distressing. They might include:

  • irritated skin around your anus
  • swelling and redness around your anus
  • fever if you also have an abscess
  • constant, throbbing pain
  • unable to control bowel movements
  • smelly discharge from near your anus
  • pus or blood in your stools

• How is an anal fistula diagnosed? icon plus

  Your GP will discuss your symptoms with you. They may also carry out a physical examination of your back passage. Depending on your symptoms, they may also recommend other tests for a later date.
  
  These might include:

  • an MRI scan: MRI scans also produce high-quality images but they tend to be used for recurrent fistulas or complex fistulas brought on by Crohn's disease. 
  • an endoanal ultrasound: An endoanal ultrasound is a quick scan that can produce high-quality images of your insides. It tends to be used if anal fistulas are of some clinical concern. 

   

• Potential treatment options icon plus

  Quite often, the only way to get rid of anal fistulas is surgery. Your consultant may recommend inserting a seton (a loop of thread that allows drainage and healing of the fistula) or a fistulotomy, which involves cutting the anal fistula so that it heals into a flat scar.
  
  There are other surgical options, including covering the end of a fistula tunnel with a flap of tissue, small clip or filling it with a special glue. Your consultant will recommend the best course of action for you.