Health Encyclopedia

Anorectal Abscess

Many glands are found within the body’s anus. If one of these glands becomes clogged, it can get infected, and an abscess can develop. An anorectal abscess is a collection of pus under the skin in the area of the anus and rectum. 

Symptoms

These are possible symptoms of an anorectal abscess:

  • Pain or discomfort near the anus or buttocks

  • Fatigue

  • Fever

  • Night sweats

  • Constipation or painful bowel movements

  • Swelling or redness near the anus

  • Lump or painful hardened tissue near the anus

  • Pain in the lower abdomen

  • Pus drainage near the anus or buttocks

Who’s at risk

These conditions may increase your chance of developing an anorectal abscess:

  • Pregnancy

  • Diabetes

  • Crohn’s disease, an inflammatory bowel condition

  • Certain medications, such as chemotherapy drugs for cancer treatment

  • Drugs that suppress the immune system after an organ transplant

  • Foreign objects placed in the rectum (usually during sex)

  • Anal fissures, or cracks, related to persistent constipation

  • Sexually transmitted disease (STD)

Diagnosis

In most cases, your health provider can diagnose an anorectal abscess through a digital rectal exam. This test involves the doctor inserting a gloved, lubricated finger into your anus. In some instances, a doctor will need to do a proctosigmoidoscopy. This is a test in which a flexible tube with a light and a camera is placed in the anus to see the area. In other instances, an MRI, CT scan, or ultrasound might be needed to find out where the abscess is.

Treatment

The doctor will probably treat your anorectal abscess by puncturing the skin near the anus so the pus can drain. This relieves the uncomfortable pressure and lets the tissues heal. Often the procedure can be done in a doctor’s office. If you have a large or deep abscess, you might need to be in the hospital, where doctors can more carefully watch your condition as the abscess is drained. You may also need to be in the hospital if your immune system is weak and you are prone to infection. In these cases, you might be given local anesthesia to help ease pain.

Complications

About half of people with an anorectal abscess develop an anal fistula. This is an abnormal opening in the skin near the anus as pus erupts from the abscess and seeps out. A fistula usually requires surgery to repair and close. Pain, infections, and recurrence are other potential complications of anorectal abscess.

Prevention

You can reduce your chances of developing this condition by managing diabetes, STDs, and other risk factors.

When to call the doctor

An anorectal abscess requires immediate medical attention before other complications happen. If you have any pain, discomfort, or swelling in the anus or rectum, see your doctor to find out the cause.



Medical Reviewers:

  • Kidd, India, RN, BSN, MBA
  • Sohrabi, Farrokh, MD