An anorectal abscess is a collection of pus in area of the anus and rectum.

Common causes include:

• Blocked gland in the area
• Infection of an anal fissure
• Sexually transmitted infection

Deep rectal abscesses may be caused by intestinal disorders such as Crohn's disease or diverticulitis.

The following factors increase your risk for an anorectal abscess:

• Anal sex
• Diabetes
• Inflammatory bowel disease (Crohn's disease and ulcerative colitis)
• Weakened immune system

The condition may occur in infants and toddlers who are still in diapers and who have a history of anal fissures.

• Constipation (may occur)
• Discharge of pus from the rectum
• Fever
• Lump or nodule, swollen, red, tender at edge of anus
• Pain associated with bowel movements
• Painful, hardened tissue

In infants, the abscess often appears as a swollen, red, tender lump at the edge of the anus. The infant may be fussy from discomfort, but there are generally no other symptoms.

A rectal examination may confirm that you have an anorectal abscess. A proctosigmoidoscopy may be done to rule out other diseases.

Treatment involves surgery to drain the abscess.

Warm sitz baths (sitting in a tub of warm water) may help relieve pain and swelling, and may help make the abscess easier to drain.

Your doctor may prescribe pain medication and antibiotics.

With prompt treatment, a patient usually does well. Infants and toddlers usually recover very quickly.

• Anal fistula
• Body-wide infection
• Problem keeps coming back (recurrence)
• Scars

Call your health care provider if you notice a rectal discharge, symptoms of an anorectal abscess develop. You should also call if you have fever, chills, or other new symptoms after being treated for this condition.

Prevention or prompt treatment sexually transmitted diseases may prevent this cause of anorectal abscesses. Use condoms during intercourse, including anal sex, to prevent such infections.

Frequent diaper changes and proper cleaning during diaper changes will help prevent both anal fissures and perianal abscesses in infants and toddlers.