A tear in the lining of the lower rectum (anal canal) that causes pain during bowel movements. Anal fissures don't lead to more serious problems.
Most anal fissures heal with home treatment after a few days or weeks. These are called short-term (acute) anal fissures. If you have an anal fissure that hasn't healed after 8 to 12 weeks, it is considered a long-term (chronic) fissure. A chronic fissure may need medical treatment.
Anal fissures are a common problem. They affect people of all ages, especially young and otherwise healthy people.