Crohn’s disease can cause anal fistulas, which are tunnels that go from your anus to the surface of the skin around your anus.

They usually begin as an infection in one of your anal glands and can result from abscesses or inflammation caused by ulcers or sores.

If you have an anal fistula due to Crohn’s disease, you may experience symptoms that include:

  • anal pain
  • swelling near your anus
  • drainage of pus from an opening in the skin around your anus

The pain and swelling near your anus may improve and return. You may also develop a fever.

A doctor may diagnose an anal fistula with a physical exam and imaging.

Imaging techniques, such as CT or MRI scan, can help the doctor see the tract made by the fistula.

Anal fistulas rarely close on their own and typically require surgery to close. Anal fistulas from Crohn’s disease typically won’t heal unless the Crohn’s disease is managed with biologics.

If a fistula occurs with an abscess, you may need a seton to allow it to drain as well as antibiotics. A seton is a band placed in the fistula and tightened over time to help the fistula drain and heal.

Commonly used procedures to treat fistulas include:

Fistulotomy

During a fistulotomy, the surgeon opens the fistula and packs it with gauze to help it heal from the inside out. This is usually performed as an outpatient procedure.

Depending on the size and severity of the fistula, a doctor may perform the procedure in their office, using a local anesthetic to numb the area, or in a hospital operating room where you’ll receive general anesthesia.

Fistulectomy

During a fistulectomy, the fistula is completely removed. A doctor will perform this procedure in a hospital operating room where you’ll receive general anesthesia.

Other treatment

You may need antibiotics if the fistula results from an infection.

After a procedure, a doctor may prescribe pain medications as you recover. They will likely provide guidelines on keeping the wound clean.

They may also prescribe medication to prevent constipation if needed.

Learn more about Crohn’s disease complications and how to prevent them.