This symptom is a symptom of anal fissure. Anal fissures occur when dry stool cracks the skin around the anus, and the fissures are often located in the anterior mid-anus or posterior mid-anus. Because these two areas are the most exposed to the stimulation of dry stool, they are most likely to produce fissures. The main clinical manifestations of anal fissure are anal pain during defecation and bleeding during stool, because the nerves around the anus are particularly sensitive, which in turn produces spasm of the anal sphincter. Therefore, the spasm of the anal sphincter is induced when the patient has a bowel movement, which is accompanied by paroxysmal cutting pain that is more intense and often lasts for several hours before it is relieved, and the patient has similar symptoms when he has a bowel movement. Patients with anal fissures generally have less blood in the stool, often manifesting as blood from wiping on hand paper.