Anoscopy is a basic and routine examination in anorectology. The anoscope consists of two parts, one is the anoscope trocar and the other is the plug inserted in the middle. There are metal anoscopes and plastic anoscopes, the metal ones can be used many times and the plastic ones are disposable anoscopes. Nowadays, disposable anoscopes are mostly used in clinical practice to avoid infection. When doing the examination, the patient usually adopts the side-lying or knee-chest position, instructs the patient to breathe deeply, relaxes the anus, gently inserts the anoscope with the inserted core, and then withdraws the core, through which the tubular cannula of the anoscope can observe whether there are lesions such as congestion, ulcers, polyps and tumors in the rectal mucosa. Then the anoscope is slowly pushed to the dentate attachment of the anus to see if there are any internal hemorrhoids, internal orifices of anal fistula, papillary hypertrophy or anal cryptitis.