Once the anus itches unbearably at night, consider intestinal parasitic infection, perianal eczema, hemorrhoids, etc. The reasons are: first, the most common is perianal eczema, the perianal area is in a humid environment for a long time, especially at night, the body’s own phytoncotic nerves are too excited, easily triggering itching at night. The treatment should use potassium permanganate lotion to clean around the anus, wipe clean and then use erythromycin ointment to apply to the affected area. Second, consider the intestinal parasitic infection, you can take intestinal worm cleaning intestinal tract. Third, hemorrhoids, treatment should be used Ma Yinglong hemorrhoid cream for the affected area, often use potassium permanganate lotion for cleaning around the anus, cleaning with a sitz bath.