There are many reasons that lead to the whitening of the human anus, can be summarized into three main categories of reasons: First, the rectum and perianal lesions caused by, mainly including hemorrhoids, perianal abscess, anal fistula, will form abscesses around the anus or broken, so that the environment around the anus for a long time wet, resulting in the anus, the surrounding skin color whitening. Second, pigmentation diseases caused by the appearance of pigmentation diseases is mainly caused by genetic factors, that is, congenital whitening of the anus, part of the patient is caused by long-term living environment as well as diet. Third, neurological skin inflammation caused by long-term mental stimulation, causing blood circulation around the anus as well as the supply of obstacles, triggering itching, anal skin whitening.