Whether or not the use of proton pump inhibitors (PPIs) leads to the development of Clostridium difficile (C. diff) infection has been an ongoing question.  A recent article in Pharmacotherapy studied this question in a retrospective, single-center, cohort study of over 41,000 patients.  These authors found an association between the use of at least one dose of a PPI and both the rate and severity of hospital-acquired C. diff infection.  Do you agree?  Have you found that patients at your institution who have received PPIs are more likely to develop C. diff infection?  Please comment.