Anorectal pain is the most common symptom occurring in anorectal diseases. Due to anatomy and physiology, pain in anorectal diseases mostly occurs in the lower abdomen, perineum, anal margin and lower rectum. Diseases that cause anal pain can be divided into two categories according to their causes of pain and suffering. 1, anal pain and pain related to defecation: Patients feel burning pain during defecation, and then periodic severe pain after defecation, often lasting ten minutes to several hours, most of this situation is caused by anal fissure. Patients with a history of prolapsed internal hemorrhoids, the pain is mostly caused by the inability of the internal hemorrhoids to retract after defecation, resulting in local edema and persistent pain, most of these cases are strangulated internal hemorrhoids. Patients who feel pins and needles pain on one side of the anus during defecation and the pain will disappear naturally after a few minutes of defecation are mostly suffering from anal cryptitis. If the pain suddenly occurs during defecation and a purple-black round lump appears on the side of the skin of the anus, and the lump is shiny if the edema is serious and accompanied by persistent pain, it should be considered a thrombosed external hemorrhoid. 2.Anal pain and pain unrelated to defecation: redness and swelling around the anus for unknown reasons, accompanied by fever and other systemic symptoms, swelling and pain around the anus and in the anal canal, and constantly aggravated, and sometimes a lump can be touched around the anus, and some have a feeling of falling, most of them are symptoms caused by infection around the anus. If there is long-term and increasing anal pain, accompanied by a feeling of falling and increased frequency of stool, and occasionally an irregular lump can be felt in the anus, the occurrence of anal canal cancer should be suspected. There are also a few cases of anal pain caused by foreign bodies. Some people mistakenly eat chicken bones, fish spines or melon seeds with shells, which are embedded in the anal canal and cause sudden pain in the anal canal, and the pain worsens when they have a bowel movement. In some cases, the foreign body is pushed in through the anus.