An anal fissure is a narrow tear that extends from the muscles that control the anus (anal sphincter) up into the anal canal. These tears usually develop when anal tissue is damaged during a hard bowel movement or when higher-than-normal tension develops in the anal sphincters.
Symptoms of an anal fissure include a sharp, stinging, or burning pain during a bowel movement. The pain, which can be severe, may last a few hours. You may also notice spots of bright red blood on toilet tissue. This blood is separate from the stool.
Minor anal fissures can often be helped to heal by drinking more fluids, eating a high-fiber diet, allowing enough time for a bowel movement, and using stool softeners.