An anal fissure is a small cut or tear in the lining of the anus. The crack in the skin causes severe pain and some bright red bleeding during and after bowel movements. At times the fissure is deep enough to expose the muscle tissue underneath. An anal fissure may occur as a result of childbirth, straining during bowel movements, or long bouts of constipation or diarrhea. Anal fissures can also be the result of certain medical conditions such as inflammatory bowel disease (IBD), infection, and cancer. An anal fissure can affect people of all ages, and it’s often seen in infants and young children. Constipation is a common problem in these age groups. An anal fissure usually isn’t a serious condition. In most cases, the tear heals on its own within four to six weeks. In cases where the fissure persists beyond eight weeks, it’s considered chronic, or long term.