Background Underfeeding is common among adult patients receiving enteral nutrition. Constipation and diarrhea have been associated with low enteral nutrition volume in critically ill patients. In patients with diarrhea, Clostridium difficile is often suspected and tested for, although medications, illness, or enteral formulas are usually the cause. The use of bowel protocols to proactively address constipation, diarrhea, and inappropriate testing for hospital-onset C difficile infection, thereby improving enteral nutrition, remains unclear. Objective To evaluate the efficacy of implementing protocols to decrease constipation, diarrhea, and inappropriate testing for hospital-onset C difficile infection, and to deliver larger enteral nutrition volumes in a critical care unit. Methods A prospective convenience sample was used. The primary outcome was the proportion of patients receiving greater than or equal to 80% of their prescribed caloric volume 1 week (minimum 4 days) after initiating enteral nutrition. Rates of testing for hospital-onset C difficile infection were analyzed before and after the protocol was implemented. Results After the protocol was implemented, patients experienced significant increases in delivery of enteral nutrition volume—up to 78% of the goal volume ( P = .048). The standardized infection ratio of hospital-onset C difficile infection decreased 43% ( P = .04). Conclusions The implementation of bowel protocols improved delivery of total enteral volumes and reduced inappropriate testing for hospital-onset infections with C difficile , and they may improve patient safety and facilitate positive patient outcomes.