The leaves of Annona senegalensis are traditionally used for the treatment of different diseases in Nigeria, including gastrointestinal disorders. The anti-diarrheal and ulcer-protective activities of its ethanol extract were determined in Wistar rats. This extract was investigated for castor oil-induced diarrhoea, intestinal transit time and castor oil-induced enteropooling in rats. The leaf extract was also tested for its ulcer protective potentials in acetylsalicylic acid, ethanol and stress-induced ulceration in rats. The phytoconstituents and oral acute toxicity of the leaf extract were also assessed. The extract significantly reduced the frequency of faecal dropping in castor oil-induced diarrhoea. It also inhibited the masses and volumes of intestinal accumulation in castor oil-induced enterpolling in rats. The distance travelled by charcoal meal was as well reduced. The phytochemical tests revealed the presence of alkaloids, saponins, tannins, flavonoids, terpenoids, and anthraquinone. However, the LD50 was greater than 5000 mg/kg in rats. The ethanol leaf extract of A. senegalensis exhibited strong antidiarrheal and ulcer protective activities, thus justifying its folkloric use by the local population against gastrointestinal disorders.