Common Gastrointestinal Infections.

Gastrointestinal infections account for a large burden of acute and chronic disease, with diarrhea being the most common manifestation. Most cases are due to viruses, with norovirus being the most common, whereas bacteria and parasites are also important contributors to acute and chronic gastrointestinal infections and their sequelae. Nontyphoidal Salmonella species cause the most hospitalizations and deaths in the United States. This article reviews an evidence-based approach to diarrhea evaluation with a focus on pathogen-specific testing and management for the most common viral, bacterial, and parasitic causes in the United States.