Anal and Rectal Abscess

An anal abscess, also known as a rectal abscess, is an infected pustule located near the anus or rectum. Most anal abscesses are the result of glands within the anal canal spontaneously becoming clogged, allowing bacteria or fecal matter to accumulate and infect the gland. This infection becomes a pus-filled cavity called an abscess. Approximately 50% of patients with an anal or rectal abscess may eventually develop an anal fistula, which is an infected tunnel that forms between the anal canal and the skin near the anus.


Although there is no known cause for anal and rectal abscesses, the American Society of Colon and Rectal Surgeons reports 90% of abscesses are the result of an acute infection within an anal gland. Additionally, up to 50% of anal and rectal abscesses develop into fistulas that cause recurrent abscess formation.

Risk Factors

Patients with autoimmune disorders or immuno-compromised conditions such as diabetes and inflammatory bowel disease generally have a greater risk of developing an anal and rectal abscess. However, most abscess formations develop spontaneously with no fault of patients activity or condition.


The most common symptoms of an anal and rectal abscess include:

  • Redness, swelling, tenderness, or a mass around the anus
  • Anorectal pain
  • Fever
  • Rectal bleeding
  • Painful urination
  • Drainage from the perianal skin (anal fistula)


Treatment for an anal and rectal abscess generally requires surgical drainage. This minimally invasive procedure is usually performed with a local and/or general anesthetic in a clinical setting (physician’s office or operating room). Anal or rectal abscesses that are extensive may require general sedation and operating room for better surgical drainage. Most anal and rectal abscesses that receive surgical drainage resolve and do not demand further treatment. However, recurring anal and rectal abscesses may indicate an anal fistula, which typically warrants further investigation and outpatient surgical management for treatment.