Abstract: Objective:To investigate the effect of orally taking Hengkangzhengqing on bowel preparation of patients before undergoing colonoscope examination.Methods:A total of 128 patients needed to carry out colonoscope were selected and divided into Hengkangzhengqing group and mannitol group randomly.The data were collected by questionnaire and observation methods.Then the scores of bowel preparation for colonoscope of the two groups were ranked and compared with each other.Results:The total effective rate of bowel cleaning with Hengkangzhengqing was 95.6%,which was higher than in mannitol group 85.0% (P<0.05).Conclusions:The effect of orally taking Hengkangzhengqing on bowel preparation is remarkable for patients.It has lower incidence of adverse reactions and is easy to manipulate.It is a good method for bowel preparation for patient s before colonoscope examination.