What is an anorectal abscess?

An anorectal abscess is an infection that causes a pocket of pus to form near the anus or rectum. It often begins when one of the small glands inside the anal canal becomes blocked and infected.

This condition can become painful quickly and may make sitting, walking, or having a bowel movement uncomfortable. Early treatment can help relieve symptoms and lower the risk of complications.

Most anorectal abscesses develop from an infection in a blocked anal gland. Certain health conditions can increase the risk, including:

• Crohn’s disease or other inflammatory bowel diseases
• Diabetes
• A weakened immune system
• Anal fissures
• Sexually transmitted infections
• Pregnancy

Symptoms

An anorectal abscess can cause symptoms that range from mild discomfort to severe pain. Many people notice symptoms that worsen over a few days.

Common symptoms may include:

• Constant pain or throbbing near the anus
• Swelling or redness around the anal area
• Fever or chills
• Pain during bowel movements
• A tender lump near the anus
• Drainage of pus or fluid
• Fatigue or feeling unwell
• Discomfort when sitting

How is it diagnosed?

A healthcare provider usually diagnoses an anorectal abscess with a physical exam and a review of your symptoms. The area around the anus may be checked for swelling, tenderness, or drainage.

In some cases, additional testing may be needed to see deeper areas of infection. These tests can include imaging studies such as an MRI, CT scan, or ultrasound. A scope exam may also be used to examine the rectum and anal canal more closely.

How is it treated?

Treatment focuses on removing the infection and relieving pressure caused by the buildup of pus. In most cases, the abscess needs to be drained through a small opening in the skin.

Smaller abscesses may be treated in an office setting using local anesthesia. Larger or deeper infections sometimes require surgery or hospital care. Antibiotics may also be prescribed, especially for people with diabetes, weakened immune systems, or signs of spreading infection.

Most people begin to feel better soon after drainage, but healing time depends on the size and location of the abscess. Follow-up care is important because some people develop an anal fistula, which may require additional treatment.