Delayed gastrointestinal (GI) motility is frequent adverse effect associated with chemotherapy, and induced by serotonin releases from enterochromaffin cells. Ijintang-gamibang (IJG) is a digestive polyherbal formula has been traditionally used in Korea and consisted of 8 types of medicinal herbs. This study was conducted to determine whether or not IJG aqueous extracts can prevent delayed GI motility induced by the antineoplastic drug cisplatin chronically administered, once per week for five consecutive weeks (2 mg/kg). 200, 100 and 50 mg/kg of IJG extracts were orally administered, once a day for 14 days from fourth cisplatin treatment, and the changes in body weight gain, fecal parameters, gastrointestinal transit ratio and histopathology were observed. In addition, pylorus gastrin and serotonin contents were also measured with immunohistochemical observations of enterochromaffin cells contains gastrin and serotonin, as compared with ondansetron, a serotonin 5-HT3 receptor antagonist, 1 mg/kg. Cisplatin treatment related body weight decreases, delayed GI motility, decreases of fecal water contents were significantly and dose-dependently inhibited by oral treatment of IJG extracts, and they also inhibited the pylorus gastrin and serotonin changes induced by cisplatin treatment. The overall effects of IJG 100 mg/kg were similar to that of ondansetron 1 mg/kg. The present results supported that IJG aqueous extracts have favorable ameliorating effect on the delayed GI motility induced by chemotheraphy, modulated the GI enterochromaffin cells, serotonin and gastrin-producing cells with antioxidant effects. This effect of IJG may help improve accompanying gastrointestinal symptoms by chemotherapy.