The main symptom of an anal fissure is pain (often severe) during and after having a bowel motion. It may be associated with some bleeding. It is often brought about by a period of constipation. Treatment focuses firstly on keeping the motions soft so that they are easy to passed and secondly on trying to reduce spasm in a anal sphincter muscles. This is usually achieved with creams including Rectogesic (GTN) and Diltiazem cream. The majority (up to 80%) of fissures heal with these simple measures, but for those that do not, a Botox injection into the anal sphincter is usually effective.