The examination of anoscopy includes the preparation before the examination, the length of the examination, and the operation process. 1. Preparation before the examination: patients should fast for 12 hours before the anoscopy and need to take laxatives to remove the contents of the digestive tract. Before the examination, the patient also needs to use sedative drugs to reduce their discomfort. The patient is positioned in a side-lying position with the knees bent toward the chest. 2. Examination length: Generally speaking, the examination length of anoscopy is about 20-30 minutes, the specific time is related to the examiner’s skillful operation and the cooperation of the examinee. 3. Operation process: The examiner holds a fiber catheter with colonoscope and enters through the patient’s anus, and injects gas and a small amount of water into the local organs and tissues, so that the intestinal tract is maintained in the state of distension and the local fecal residues are flushed out, in order to better observe the internal condition of the intestinal tract. Due to the need for a definitive diagnosis, the examiner will use the attached sampling forceps to take a biopsy of the localized tissues of the subject and send it to pathology for clarification of its nature. During the examination, photos will be taken throughout the normal or suspected lesion areas to keep the pictures of the examined.