Fissure under the anus, accompanied by severe pain in the anus, and the symptom of blood in the stool, then it is possible that anal fissure occurs, at this time the first step is to soften the stool, that is, try to keep the stool as thin and soft as possible, and you can take laxative medicines orally, such as Ma Ren Pills, Sophora Pills, and so on. Dry stool will repeatedly stimulate the fissure, causing it to be difficult to heal. In addition, you can use warm water to sit on the anus after the stool to relieve the spasm of the anal sphincter, to reduce the symptoms of pain. You can also use hemorrhoidal medication, such as anal ointment or Ma Ying Long Hemorrhoidal Cream to apply to the fissure to accelerate its healing.