An anal fissure is a cut or tear occuring in the anus (the opening through which stool passes out of the body) that extends upwards into the anal canal. Fissures are a common condition of the anus and anal canal.Patients with anal fissures almost always experience anal pain that worsens with bowel movements. The pain following a bowel movement may be brief or long lasting; however, the pain usually subsides between bowel movements. The pain can be so severe that patients are unwilling to have a bowel movement, resulting in constipation and even fecal impaction. Moreover, constipation can result in the passage of a larger, harder stool that causes further trauma and makes the fissure worse. The pain also can affect urination by causing discomfort when urinating (dysuria), frequent urination, or the inability to urinate. Bleeding in small amounts, itching (pruritus ani), and a malodorous discharge may occur due to the discharge of pus from the fissure.