Background: The folkloric use of Cochlospermum planchonii is yet to be substantiated with scientific evidence.Aim: The aqueous extract of C. planchonii leaves was evaluated for anti-diarrhoeal activity at 125, 250 and 500 mg/kg body weight in female Wistar rats.Setting: This research is a phytopharmacological investigation.Methods: Animal were monitored for indicators of diarrhoea in the 3 models after treatments.Results: An aqueous extract of C. planchonii leaves contained 10 secondary metabolites, with alkaloids (16.05 mg/L) occurring the most, whilst quinones (0.7 mg/L) were the least. The extract significantly (p 0.05) prolonged the onset time of diarrhoea, decreased water content, fresh weight and total number of wet faeces in a dose-dependent manner, and increased the percentage inhibition of defecation. The extract produced dose-specific changes on intestinal superoxide dismutase, glucose and reduced glutathione whereas the levels of intestinal Na+/K+-ATPase, alkaline phosphatase, catalase, nitric oxide were significantly (p 0.05) increased in the castor oil-induced diarrhoeal model. The masses and volumes of intestinal fluid decreased significantly (p 0.05) whereas the inhibition of intestinal fluid content increased like those of atropine-treated diarrhoeal rats in the enteropooling model. The extract dose-dependently decreased the distance travelled by the charcoal meal and increased the intestinal nitric oxide and acetylcholinesterase in the charcoal meal transit model.Conclusion: The aqueous extract of C. planchonii leaves exhibited anti-diarrhoeal activity via anti-motility and anti-secretory means. The flavonoids, alkaloids, tannins, phenolics and saponins might have acted to enhance the activities of Na+/K+-ATPase, antioxidant enzymes, intestinal glucose levels and the neurotransmitters.