Anorectal Abscess

Treatment

The main treatment for an anorectal abscess is to drain it. At Mayo Clinic, this procedure is done by a colon and rectal surgeon. Where the abscess is located usually determines how the surgeon drains it. After the abscess has been drained, patients with conditions that make them more susceptible to infection are usually prescribed antibiotics.

Draining Approaches

Perianal Abscess (in the Area Surrounding the Anus)

The surgeon removes the most prominent part of the abscess with a crisscross cut. The resulting flaps of skin are then trimmed and the abscess is thoroughly scraped and flushed out. The surgery is usually performed as an outpatient procedure using local anesthesia.

Ischioanal Abscess (between the Ischium and Anus or Rectum)

If the abscess is small, the surgeon treats it similarly to a perianal abscess. If the abscess is large and has spread to one or both sides — called a horseshoe abscess — it must be drained in the operating room, with the patient under regional or general anesthesia.

Intersphincteric Abscess (between the Internal and External Anal Sphincter Muscles)

The surgeon makes an incision into the anal canal lining and down through the internal sphincter muscle to reach and drain the abscess. The surgery is usually performed in an operating room with the patient under regional or general anesthesia.

Supralevator Abscess (above the Levator Ani Muscle)

Surgery to drain a supralevator abscess will depend on the origin of the abscess. If the abscess is an intersphincteric abscess that has extended upward, the surgeon will drain it into the rectum. If the abscess is an ischioanal abscess that has extended upward, the surgeon will drain it through the ischioanal fossa (hollow area between the anus and the ischium bone) and out through the skin. If the abscess is due to an intra-abdominal disorder such as Crohn's disease or diverticulitis, the abscess will likely be drained during surgery to treat the other disorder.