1 Pediatric Gastroenterology and Cystic Fibrosis Unit, Department of Human Pathology in Adulthood and Childhood "G. Barresi", University Hospital of Messina, Messina, Italy.
2 Pediatric Gastroenterology and Cystic Fibrosis Unit, Department of Human Pathology in Adulthood and Childhood "G. Barresi", University Hospital of Messina, Messina, Italy. Electronic address: romanoc@unime.it.