Section of Gastroenterology, Hepatology, and Nutrition, Department of Pediatrics and the Digestive Health Institute, Children's Hospital Colorado and University of Colorado School of Medicine, Aurora, CO. Electronic address: shikha.sundaram@childrenscolorado.org. Section of Pulmonary Medicine, Department of Pediatrics, Children's Hospital Colorado and University of Colorado School of Medicine, Anschutz Medical Center, Aurora, CO. iC42 Clinical Research and Development, Department of Anesthesiology, University of Colorado School of Medicine, Aurora, CO. Biostatistical Core of Research Institute of Children's Hospital Colorado and University of Colorado School of Medicine, Anschutz Medical Center, Aurora, CO. Section of Gastroenterology, Hepatology, and Nutrition, Department of Pediatrics and the Digestive Health Institute, Children's Hospital Colorado and University of Colorado School of Medicine, Aurora, CO. Pediatric Pathology, Department of Pathology, University of Colorado School of Medicine, Aurora, CO.