Tetraclinis articulata (Thuya of Barbary), endemic to North Africa, is used as a traditional medicine for the treatment of many diseases . We investigated the antidiarrhoel properties of the butanol extract of Tetraclinis articulata (BETA) in male and female Swiss albino mice to support its traditional use. The antidiarrhoeal activity of the plant extract was evaluated in a model of castor oil-induced diarrhoea model in mice and compared to loperamide (a reference inhibitor of diarrhoea). The effect of (BETA) on gastrointestinal motility was determined by the oral administration of charcoal and Castrol oil-induced intestinal fluid accumulation (enteropooling).The (BETA) showed remarkable antidiarrhoeal activity significantly inhibited gastrointestinal motility and castor oil induced enteropolysis (68,18%), more than to the inhibition achieved in loperamide treated mice (60,16%). The second aim of the present study was to evaluate the anti-ulcerative activity of The (BETA), it produced percent protection of control colitis by 77, 40%, while the standard drug (aspirin) produced 81,39% protection. We conclude that Tetraclinis articulata extracts are potential sources of new anti-ulcer agents and antidiarrhoeal drugs.