Acute diarrhoea is a leading cause of deaths amongst children below five years. Annona senegalensis plant is used traditionally to treat diarrheoa. This study aims at evaluating the antidiarroeal potency of the aqueous extract of the root and stem bark of Annona senegalensis. Antimicrobial, antioxidant and antidiarrhoeal activity of aqueous extracts of the root bark, stem bark and mixture of stem and root bark of Annona senegalensis was assessed. Stool inhibition, enteropooling, electrolyte secretion and gastro-intestinal motility potential of the extract were assessed in castor oil induced diarrhoeic rats following administration of 100, 200 and 400 mg/kg body weight of aqueous extracts of stem bark alone, root bark alone and the mixture of root and stem bark. The extract showed good antioxidant property. The mixture of aqueous root and stem bark extract of Annona senegalensis improved antimicrobial activity against three diarrhoea causing micro-organism; Escherichua coli, Bacillus cereus and Shigella dysentriae. All the extracts inhibited stooling by a percentage ranging from 17 – 21.9 in a dose independent manner. The root extract did not reduce number of stool as effective as stem extract. The root extract significantly reduced weight and volume of intestinal fluid. 200 mg/kg body weight of the aqueous root bark extract inhibited gastrointestinal transit the most. The mixture of root and stem bark extract exhibited synergistic effect on some diarrhoea causing micro-organisms. The root exerts its antidiarrhoeal effect by reducing intestinal motility and enhancing water and nutrient absorption, while the stem exerts its effect by antisecretory mechanism.