Anorectal abscess

An anorectal abscess is a pocket of pus in the tissue near the end of the rectum (anus). Most abscesses are caused by a blocked anal gland that develops an infection.

Other possible causes of an anorectal abscess include:

  • Infection in an anal fissure.
  • Complications of diseases that affect the colon, such as Crohn's disease, inflammatory bowel disease, or diverticulitis.
  • Sexually transmitted infections.

Symptoms of an anorectal abscess include:

  • A painful swelling (mass) around the anus.
  • Drainage of pus from the anus.
  • Fever.
  • Pain in or around the anus.
  • Pain when passing stool.

A person should see a doctor if an anorectal abscess is suspected. Treatment is needed to prevent worsening of the infection and serious illness.