Children between 15 days and 5 years of age with symptoms of AGE (i.e., diarrhea [3 episodes within 24 hours] and/or vomiting [any episodes within 24 hours] lasting for ≤10 days) who visited hospitals, EDs, and outpatient clinics at the 3 sites from October 2008 through September 2009 were eligible to be enrolled in the study. Stool specimens were obtained within 14 days of the date of visitation or admission for AGE symptoms (95% specimens were collected within 7 days).