Objective: To analyze the medication rule of herbal fumigation prescription for pruritus ani based on TCMISS. Methods: Herbal fumigation prescriptions of treating pruritus ani were collected from CNKI, VIP and Wanfang database from 1989 to 2016, the association rules between the herbs, the nature, tastes and the entering meridians, the usage frequency of different herbs were analyzed in the prescriptions. Results: The drugs in the top three frequencies were Kushen(Sophora flavescens), Shechuangzi[Cnidium mo...