Aim: To evaluate the antidiarrhoea effect of hydromethanolic leave extract of I. asarifolia (HLEIA) on castor oil-induced diarrhea. Place and Duration of Study: Department of Biochemistry, Faculty of Life sciences, Kebbi State University of Science and Technology, Aliero, Kebbi state, Nigeria. P.M.B.1144. Kebbi State. Nigeria, between February 2015 and September 2016. Methodology: In a continuous effort to search for bioactive agents from medicinal plants, the antidiarrhoea activity of I. asarifolia was investigated. The effect of hydromethanolic leave extract of I. asarifolia (HLEIA) on castor oil-induced diarrhoea, gastrointestinal transit and intestinal fluid accumulation (enteropooling) were assessed in albino rats. Qualitative phytochemical analysis was carried out using standard procedures while acute oral toxicity studies was determined using the staircase method. Results: The phytochemical analysis showed the presence of alkaloid, terpenoid, tannin, saponin, phenols. The LD50 was estimated to be greater than 3000 mg/kg since there was no mortality recorded after 14 days of acute oral toxicity studies. Sub-chronic administration of graded doses (150 – 600 mg/kg) of HLEIA significantly (p<0.05) reduced diarrhoea episodes, decreased gastro intestinal movement and inhibited intestinal fluid accumulation compared to the control. The antidiarrhoea effect of treated group (600 mg/kg ) was comparable to that of the standard drug Loperamide. Conclusion: The findings of the present study scientifically validate the use of I. asarifolia in the treatment of diarrhoea.