White rice grains growing in the anus may be caused by warts, perianal herpes, perianal inflammation, folliculitis and other diseases. 1. warts: warts belong to sexually transmitted diseases, mainly due to the infection of human papilloma virus and the formation of the anus can be in the anus skin at the performance of white granular bumps, and gradually grow up long more. 2. Perianal herpes: Perianal herpes is mainly caused by local infection with the herpes virus, the skin at the anus can appear rice grains, papule-like white particles, accompanied by a tingling sensation, and so on, with a certain degree of contagiousness. 3. Perianal inflammation: do not pay attention to anal hygiene, the local easy to stool after fecal residue, can lead to local breeding of bacterial infections, can appear in the perianal inflammation, can also be manifested as granular protruding pus tip, accompanied by local pain, redness and swelling of the performance. 4. Folliculitis: purulent inflammation of the perianal skin follicles, can appear locally red papule-like elevation, with the aggravation of the infection, can lead to localized pus, white pus crust-like changes. When the anus appears white grains, need to go to the hospital in a timely manner, under the guidance of specialists to actively carry out appropriate treatment, help the early cure of the disease, to avoid aggravation.