The growing list of drug-resistant microorganisms and the persistence of deaths due to diarrhea are compelling reasons to study plants in search of new therapeutic agents. The chemical constitution and popular use of the edible fruits of Campomanesia xanthocarpa O. Berg motivated this study to assess the antimicrobial and antidiarrheal properties of the fruits. An extract in 70% ethanol was prepared, and its antimicrobial activity was tested against several strains of bacteria by the agar diffusion and microdilution methods. Antidiarrheal activity was analyzed by testing intestinal motility in an animal model. Preliminary phytochemical study indicated the presence of flavonoids, saponins, and tannins in the hydroalcoholic extract. Antimicrobial activity was significant, but the minimum inhibitory concentration proved to be higher than the maximum extract concentration tested. The extract did not show significant activity for intestinal motility. Although this fruit extract did not show great results as an antimicrobial or antidiarrheal agent, the study contributes to the search for new plant agents and could be referred to as a research protocol by investigators in this area.