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Fistulas are abnormal connections between two structures. Most commonly, they involve an area of the rectum or anus or the skin surrounding the anus. This is called fistula-in-ano. A fistula may also form between two segments of the small or large intestine, which is typically seen in disease states such as Crohn’s disease.

Fistulas often start as an abscess or infection in or around the anus. Over time, a tunnel develops. Fistulas allow bacteria to escape from the bowel and cause an infection in the subcutaneous tissues of the skin. While approximately half of patients who develop this type of abscess will completely heal without further intervention, half will go on to develop a chronic fistula, where the connection between the rectum and the skin remains open and can create ongoing problems. In the latter case, surgery is usually required.

There are many treatment options available for fistulas, but they depend on the trajectory of the tunnel under the skin. Treatment options include fistulotomy, ligation of the intersphincteric fistula tract (LIFT), rectal advancement flap, plug, glue, or a small drain.

Signs and symptoms of fistulas

  • Anal pain
  • A mass or lump in the skin by the anus
  • Drainage of pus from the skin around the anus
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