Nutrition Science, Department of Medical Affairs, Mead Johnson Nutrition, Evansville, IN 47721, USA. Clinical Research, Department of Medical Affairs, Mead Johnson Nutrition, Evansville, IN 47721, USA. University College London, Great Ormond Street, London WC1N 3JH, UK. Division of Pediatric Gastroenterology, Indiana University School of Medicine, Indianapolis, IN 46202, USA. Boston Children's Hospital, Gastroenterology, Boston, MA 02115, USA.