The anoscopy is divided into pre-screening preparation, screening and post-screening observation, as follows: 1. Pre-screening preparation: Patients need to empty the stool before the examination to avoid the observation being affected by stool during the examination. 2. Screening: The anal canal needs to be fully lubricated before the examination, and if necessary, the anus is dilated and the anoscope is slowly placed into the anus. In the process of inserting the anoscope, avoid rough force to avoid damaging the anal canal. 3.Observation after insertion: after insertion, slowly advance again to observe whether there are any abnormal lesions in the lower rectum and anal canal, and if abnormal lesions are found, biopsies can be taken under the anoscope for pathological section examination to clarify the diagnosis.