Most of the anal foreign body sensation is caused by some diseases around the anus, common diseases are anal sinusitis, hemorrhoids, anal fissure, etc., as follows: First, anal sinusitis: may be anal sinusitis, because the anal sinus opening towards the top, so the anal sinus is easy to accumulate feces and bacteria and other contaminants, resulting in anal sinus infection, perianal infection will stimulate, producing a foreign body sensation in the anus. Second, hemorrhoids: it may be hemorrhoids, the enlarged nucleus of the hemorrhoid will also stimulate the patient’s anal canal skin and produce a foreign body sensation. Third, anal fissure: anal fissure if the formation of chronic ulcers, local chronic inflammatory stimulation will also lead to anal foreign body sensation. Fourth, other diseases: also include anal papillary hypertrophy, rectal polyps prolapse and other diseases, may lead to anal foreign body sensation. So when the patient has a foreign body sensation in the anus, you need to go to the hospital and perform relevant physical examination to clarify the cause and then take the appropriate treatment.