Anal fissure is elongated ulcer which goes from the anal sphincter to the anal canal. While the patient is defecating, an ulcer irritation causes spasm of a sphincter, accompanied by severe pain and, sometimes, bleeding.
This rare illness, most commonly occurring in women, can sometimes be cured with higher content of dietary fiber in the diet and laxatives, e.g. liquid paraffin. If the fissure lasts for a long time, it will probably require a minor surgery to cure spasms and irritations. After the surgery, the ulcer is almost always quickly healed without further therapy.