Pediatric gastroenterology, hepatology and nutrition, 22(3), 270-281. Korean Society of Pediartic Gastroenterology, Hepatology and Nutrition Pediatric Gastroenterology, Hepatology and Nutrition, 22(3), 270-281. Korean Society of Pediartic Gastroenterology, Hepatology and Nutrition Pediatric Gastroenterology, Hepatology & Nutrition