ABSTRACT: The findings of the present study provide convincing evidence that methanolic root extract of M. arundinacea (MEMA) roots possesses remarkable antidiarrheal activity.  Antidiarrheal effect is rapid, long lasting, and statistically significant at both 200 and 400 mg/kg doses. However, further chemical and pharmacological studies are required to isolate the bioactive compounds and elucidate the precise mechanisms responsible for the observed pharmacological activities of this plant.