1. From the Sections of Pediatric Emergency Medicine and Gastroenterology, Alberta Children’s Hospital, Alberta Children’s Hospital Research Institute (S.B.F.), and the Section of Pediatric Emergency Medicine, Alberta Children’s Hospital (S.W.-U., J.X.), Cumming School of Medicine, University of Calgary, Calgary, the Departments of Pediatrics and Emergency Medicine, Children’s Hospital of Eastern Ontario, University of Ottawa, Ottawa (K.J.F.), the Division of Pediatric Emergency Medicine, Department of...