The common anal diseases are anal fissure and anal canalitis. The specific differential diagnosis is as follows: 1. Anal fissure: Patients have long-term constipation, dry stool and severe pain during defecation, and also accompanied by the symptoms of bright red blood. If the above symptoms appear, consider the possibility that the pain inside the anus is caused by anal fissure. 2, anal canalitis: If there are no accompanying symptoms, but only a jumping pain inside the anus, the pain caused by anal canalitis is more likely. As for the specific one, it is recommended to go to the anorectal department of a regular hospital for consultation. Experienced anorectal doctors can make a clear diagnosis through anoscopic examination, anal finger diagnosis and other conventional means.