Patients with toxin-negative Clostridioides difficile-positive diarrhea are often treated with oral vancomycin with the assumption that treatment is more beneficial than harmful. However, this hypothesis has never been formally tested, and recent studies suggest that most such patients recover quickly without treatment and can be colonized rather than infected. Fishbein et al. conducted a prospective, placebo-controlled randomized trial to systematically evaluate the effects, risks, and benefits of oral vancomycin in these patients (S. R. S. Fishbein, T. Hink, K. A. Reske, C. Cass, et al., mSphere 6:e00936-20, 2020, https://doi.org/10.1128/mSphere.00936-20). Although small, the results are intriguing and suggest the adverse antibiotic-induced effects of vancomycin outweigh the clinical benefit when colonization is more likely than disease.