Reasons for pain after hemorrhoid surgery: The first one, because the nerves of the anal canal tissue below the dentate line are very sensitive, when the anal canal tissue is surgically damaged, it can produce severe pain, which can also cause spasm of the sphincter muscle around the anus, resulting in obstruction of local blood circulation in the anus, causing local ischemia in the anus and leading to increased pain. Secondly, stimulation by defecation, due to surgical removal of diseased tissues, the formation of trauma stimulation, coupled with the patient’s fear psychology, so that the anal canal is often in a contracted state, and the anus cannot contract and relax during defecation, and fecal stimulation of the trauma can cause tear-like pain, reflexively causing spasm of the sphincter, and this pain in turn intensifies the patient’s tension and fear psychology, so that the patient’s anal canal continues to contract, leading to pain after defecation This pain in turn increases the patient’s nervousness and fear, causing the patient’s anal canal to continue to contract, leading to increased post-poo pain. Third, traumatic infection, edema, and excessive dressing can cause traumatic pain. The fourth one is the injury of surgery. When the anal canal is narrow or the skin of the anal canal is too much damaged by surgery, the patient can not defecate well and damage the trauma, which causes tearing pain.