The anus is always itchy, the main reason is many, the first, if the anal sphincter muscle relaxation, especially in elderly patients, feces or mucus is easy to flow to the perianal skin involuntarily, thus producing stimulation, causing itching, rectal fingerprinting can be touched to rectal sphincter muscle relaxation and weakness. Secondly, if you eat a lot of spicy and stimulating food or certain flavorings, can also cause perianal itching, if often wear artificial fiber fabrics or eat certain seafood, can also cause anal itching. Third, if you often take certain medicines, such as quinidine and colchicine, they can cause acute anal itching. Fourth, there may be anal fissure, anal fissure manifested as perianal visible radial fissure, local mucus oozing, will cause perianal itching. Perianal itching should actively go to the hospital, you can perform rectal palpation, if necessary, placed into the anoscopy to observe whether there are anal fissures, hemorrhoids or other diseases.