Infectious diarrhea is the fifth leading cause of death worldwide.1 In the United States, 179 million cases of acute diarrhea occur per year.2,3 Most diarrheal illnesses are self-limited and do not require evaluation or treatment beyond supportive care such as rehydration. Some infections do require antimicrobial therapy, and appropriate use of diagnostic tests and treatments may potentially minimize unnecessary costs, decrease adverse events, optimize clinical outcomes, and limit antibiotic resistance.