If possible, your doctor will perform a digital rectal exam, which involves inserting a gloved finger into your anal canal, or use a short, lighted tube (anoscope) to inspect your anal canal. However, if this is too painful for you, your doctor may be able to diagnose an anal fissure only by observation.

An acute anal fissure looks like a fresh tear, somewhat like a paper cut. A chronic anal fissure likely has the tear, as well as two separate lumps or tags of skin, one internal (sentinel pile) and one external (hypertrophied papilla).

The fissure's location offers clues about its cause. A fissure that occurs on the side of the anal opening, rather than the back or front, is more likely to be a sign of another disorder, such as Crohn's disease. Your doctor may recommend further testing if he or she thinks you have an underlying condition:

  • Flexible sigmoidoscopy. Your doctor will insert a thin, flexible tube with a tiny video into the bottom portion of your colon. This test may be done if you're younger than 50 and have no risk factors for intestinal diseases or colon cancer.
  • Colonoscopy. Your doctor will insert a flexible tube into your rectum to inspect the entire colon. This test may be done if you are older than age 50 or you have risk factors for colon cancer, signs of other conditions, or other symptoms such as abdominal pain or diarrhea.