Anal Abscess (And Anal Fistula)
(Anal Rectal Abscess; Anorectal Abscess)
An anal abscess is a pus-filled pocket located in the spaces around the anus and rectum. An abscess can be found near the surface of the anal opening or deeper in the rectum.
An anal abscess is caused by a bacterial infection. Infection may occur when there is a blockage in one or more of the anal glands that secrete mucous, or from an anal fistula.
Anal absesses are more common in men. Other factors that may increase your chance of an anal abscess include:
Symptoms depend on where the abscess is located. An anal abscess may cause:
- Painful bowel movements
- Pain and tenderness radiating from the location of the abscess if it is near the surface
- Lower abdominal pain if it is located deeper in the rectum
- Redness and swelling—visible with a surface abscess, also occurs in a deep abscess, but cannot be seen
- Pus drainage
Complications of an anal abscess may include:
Your doctor will ask about your symptoms and medical history. A physical exam will be done. An abscess near the surface of the skin may be visible. A deeper abcsess may require a digital rectal exam. The doctor will feel the inside of the anal canal for any abnormalities.
Imaging tests to look at anorectal structures may include:
- MRI scan
Surgical drainage is necessary to treat an anal abscess. The type of procedure depends on its location and depth. It is possible that you may have a drain in the wound for up to 3 weeks to help the healing process.
To help reduce your chance of an anal abscess, be sure to manage any health conditions that increase your risk of infections.
American College of Gastroenterology
American Society of Colon and Rectal Surgeons
Canadian Association of Gastroenterology
Canadian Society of Colon and Rectal Surgeons
Abcarian H. Anorectal infection: Abscess-fistula. Clin Colon Rect Surg. 2011;24(1):14-21.
Anal abscess and fistula. American Society of Colon and Rectal Surgeons website. Available at: https://www.fascrs.org/patients/disease-condition/abscess-and-fistula-expanded-information. Updated October 2012. Accessed November 9, 2015.
Anal rectal abscess and fistula. Hemorrhoid website. Available at: http://www.hemorrhoid.net/abscess.php. Accessed November 9, 2015.
Anorectal abscess. John Hopkins Medicine website. Available at: http://www.hopkinsmedicine.org/healthlibrary/conditions/adult/digestive_disorders/anorectal_abscess_134,175. Accessed November 9, 2015.
Caliste X, Nazir S, Goode T. Sensitivity of computed tomography in detection of perirectal abscess. Am Surg. 2011;77(2):166-168.
Schaffzin DM, Wong WD. Surgeon-performed ultrasound: endorectal ultrasound. Surg Clin North Am. 2004;84(4):1127-1149.
Last reviewed November 2015 by Michael Woods, MD
Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.