Perianal Abscess

Most perianal abscesses occur when bacteria or foreign material enter and clog an anal gland, or when an anal fissure becomes infected. Risk factors of perianal abscess include:

• Certain sexually transmitted diseases (STDs)
• Inflammatory bowel diseases such as Crohn’s disease and ulcerative colitis
• Colitis
• Diabetes
• Chronic diarrhoea and constipation
• Pelvic inflammatory diseases

Perianal abscesses are mainly characterised by a dull, throbbing pain in the anal or rectal region that becomes worse when sitting or defecating. The boil-like abscess may be tender and warm to the touch, and may drain pus spontaneously over time.

Perianal abscesses accompanied by fever, fatigue, chills, constipation, vomiting, extreme pain, or rectal bleeding and discharge, may be indicative of a serious infection and usually require immediate medical attention.

Most of the time, a colorectal surgeon can give a diagnosis of perianal abscess with a patient’s medical history and a physical exam. Through visual inspection and palpation, the doctor will usually check for redness, swelling and pain around the anal and rectal area, as well as distinguishing between an anal abscess and haemorrhoids.

Perianal abscesses that develop deep within the anal canal (ischiorectal abscesses) may not manifest physical symptoms and may require blood tests and colonoscopy to diagnose. Sometimes, imaging tests such as CT scan, MRI and transrectal ultrasound (TRUS) may be required.