Anal Abscess Facts

  • A perirectal abscess is a collection of pus in the deep tissues surrounding the anus.
  • By contrast, a perianal abscess is a shallower collection of pus under the skin surrounding the anus; however, both are sometimes described as an anal abscess.
  • Both types of abscesses need immediate medical attention; however, a perirectal abscess usually is the more severe infection.
  • A delay in treatment may cause serious worsening of the condition and unnecessary complications.

Anal Abscess Causes

Perirectal and perianal abscesses are thought to develop from the glands surrounding the anus; on occasion, perianal abscesses may develop from infected skin adjacent to the anus. Glands may plug up, usually leading to bacterial infection. When the glands fill with pus, they may burst inward, releasing their infected contents into the spaces around the rectum and anus. This pus causes an abscess, or pus collection, in the spaces surrounding the rectum or anus. The anal abscess may enlarge, causing pain, fever, and difficulty with bowel movements.

Certain people are more likely to develop perirectal and perianal abscesses, including those with the following medical conditions:

  • Diabetes
  • AIDS or HIV infection with low white blood cell counts
  • Crohn’s disease
  • Persons on medications that suppress the body’s immune system, such as steroids (prednisone, methylprednisolone), or those undergoing chemotherapy for cancer
  • Pregnancy
  • Placement of foreign bodies into the anus
  • Sexually transmitted diseases
  • anal fissures

Anal Abscess Symptoms

Signs and symptoms of perirectal and perianal abscesses include the following:

  • Pain in the anal area or buttocks
  • Pus drainage near the anus
  • Fever
  • A lump in the anal area
  • Painful bowel movements
  • Lower abdominal pain
  • Fatigue
  • Swelling in the anal area or buttocks
  • Night sweats

When to Seek Medical Care for an Anal Abscess

If a person suspects they have a perirectal or perianal abscess they should see a healthcare professional. The diagnosis is not always easy to make, and the healthcare professional may need to do tests or consult with specialists.

Go to an emergency department when you have any of the following symptoms:

  • High fever or shaking chills
  • Significant rectal/anal pain
  • Inability to have a bowel movement, or a painful bowel movement
  • Persistent vomiting
  • Any other unusual signs or symptoms that may indicate an emergency condition