Darkening of the anus can only be treated with decoloration if it turns white, but it may cause damage to the skin. Black anus is actually a normal phenomenon, after puberty due to changes in hormone secretion in the body, so it may lead to the body armpits, groin, anus and other parts of the pigmentation, so there will be a black problem. Darkening of the anus is not only related to the change of hormone level in the body, because this part of the folds are more prone to friction, so it is also the main reason for inducing darkening of the color. Generally do not need to be treated, if the treatment can be decoloration treatment, but due to the thin perianal skin, decoloration treatment may induce local irritation and inflammatory reaction. Black anus, it is recommended that you can consult with a regular hospital, do not treat yourself to avoid local damage.