I feel something crawling in my anus.

Consider anal pruritus, it is a common localized neurodysfunctional skin disease. Generally limited to the anus, some can spread to the perineum, vulva or scrotum.

In 20~40 years old middle-aged, elderly, young people under 20 years of age less, rarely occurs in children. Male than female more common, accustomed to quiet and infrequent exercise of people more often occur this pruritus.

Secondary pruritus has obvious causes, easy to treat. Spontaneous or unknown causes are not easy to cure, but also often relapse, accounting for about 50% of all patients. Also to exclude ascarid infection, tinea cruris and other diseases.