Because the anal skin is rich in nerves and sensitive to sensation, it is prone to pain or severe pain after stimulation, causing greater pain to patients. There are many causes of anal pain, which can be summarized as follows: 1. Inflammatory lesions. Most common, including perianal inflammation and perianal abscess. Initially, it is a burning pain, and when it is purulent, it can have jumping pain like chicken pecking, often accompanied by local skin redness and swelling. 2, anal fissure, anal canal skin ulcers. The pain is often severe and continuous during and after defecation, and may be accompanied by a small amount of fresh blood. 3. External hemorrhoid thrombosis. The pain is mostly on one or both sides of the anus, with sudden onset of pain, severe pain like a cone, more so when walking or sitting and squatting, accompanied by anal swelling and nodules. 4.Tumor. Due to the infiltration of tumor, compression and post-radiation therapy syndrome, etc. can produce pain, which is cramping pain or pumping pain, accompanied by tumor nodules. 5.Internal hemorrhoid prolapse or rectal prolapse occurs. At this time, due to tissue edema, it affects the circulation around the tapir and produces pain and even tissue necrosis. 6.Viral infection caused by perianal herpes simplex and venereal disease in the anorectal area. Including syphilis, anorectal gonorrhea, etc. Of course, all kinds of trauma to the anal area, including the anal perineum after surgery can cause pain. There are also a few pains of unknown origin.