Diarrhoea, characterized by increased frequency of stools (3 or more per 24 hrs), increased fluidity of stools and/or the presence of blood/mucus, affects people of any age, but is the third commonest disease in children in developing countries, and is responsible for about one third of all hospitalizations among children under five years. Research into drug treatment of diarrhoea, revealed that several species of Solanum are used in traditional  medicine to treat diarrhoea. Therefore, this study aimed to investigate and possibly authenticate the antidiarrhoeal activity of ethanol extracts of  S. anomalum leaves, as used in traditional medicine.  The ethanol extract of S. anomalum leaves was evaluated to authenticate its antidiarrhoeal activity using rats.  Ethanol extract  at doses of  70, 140 and  210 mg/kg was checked for antidiarrhoeal  effect using three models of small bowel transit time, castor oil induced diarrhoea, and castor oil induced accumulation of fluid. The leaf extract caused significant (p<.001) inhibition of small bowel transit time, castor oil induced diarrhoea, and castor oil induced fluid accumulation. In conclusion, the findings of this study show that the ethanol extract of  S. anomalum leaves has antidiarrhoeal properties, therefore confirming its traditional use as medicine in the management of diarrhoeal disorders.