Anoscopy, one of the most common tests used in anorectal medicine. For unexplained blood in the stool or unformed bowel movements, anoscopy can be the first choice because it is easy and inexpensive to perform and can detect early internal hemorrhoids or polyps in the rectum and anal canal. For some lesions, local excision or treatment can be performed under anoscopy. Local irrigation is also an option. For chronic inflammation of the intestine, especially in patients with proctitis with co-infection, local irrigation can be performed via anoscopy. In addition, for rectal malignant tumors, early detection under anoscopy is possible, as well as local biopsy. For malignant lesions, local excision can be performed, and for tumors smaller than 2 cm, partial excision of the mucosa is performed. For larger lesions, systematic anesthesia should be performed and radical resection should be chosen. Anoscopy is less invasive and easy to perform, and it is also easy to carry out in primary hospitals and outpatient clinics, which can detect many perianal diseases at an early stage.