Objective: In Burkina Faso as in other developing countries, the diarrheal diseases constitute a serious problem of public health. To treat diarrhea, most Burkina Faso people living in the rural areas do rely on medicinal plants. To evaluate the traditional use of Opilia celtidifolia, scientific validation is needed. Methods: The collected plant materials were dried, pulverized, and aqueous acetone extracts were prepared. The serially diluted fractions of the extracts and finally reach the flavonoid-rich fractions which assayed for antibacterial activities against selected enteropathogens by agar well diffusion method, minimum inhibitory concentration and minimal bactericidal concentration respectively. The anti-diarrheal activity was evaluated using castor oil induced diarrhea, magnesium sulphate-induced diarrhea and gastrointestinal transit test examined in animal models respectively. Results: Flavonoid-rich fractions has positive effects in a dose dependent manner against diarrhoea induced by castor oil, magnesium sulphate-induced diarrhea and gastrointestinal transit test examined in animal models. The bioactive fraction also showed good antimicrobial activity against all bacteria strains and compared to the ciprofloxacin. Conclusions: These findings indicate that the flavonoid-rich fraction possesses antidiarrheal property in rats and confirm the ethnomedicinal use of Opilia celtidifolia a valuable natural remedy for the treatment, management and/or control of diarrhea. The results provided some insight into the gastroprotective potential of this plant traditionally used by the people of Burkina Faso to treat diarrhea.