[1] Univ Roma La Sapienza, Pediat Gastroenterol & Liver Unit, I-00185 Rome, Italy
[2] Meyer Pediat Hosp, Gastroenterol & Nutr Unit, Florence, Italy
[3] G Gaslini Inst Children, Gastroenterol & Endoscopy Unit, Genoa, Italy
[4] Univ Padua, Dept Pediat Gastroenterol, Padua, Italy
[5] Univ Messina, Messina, Italy
[6] Buzzi Childrens Hosp Milan, Dept Pediat, Milan, Italy
[7] Univ Messina, Messina, Italy
[8] Spirito Santo Hosp, Pediat Gastroenterol & Endoscopy Unit, Pescara, Italy
[9] Univ Naples Federico II, Dept Pediat, Naples, Italy
[10] Maggiore Hosp, Dept Pediat, Bologna, Italy
[11] Giovanni XXIII Hosp, Dept Pediat, Bari, Italy
[12] Univ Turin, Pediat Gastroenterol Unit, Turin, Italy
[13] Univ Politecn Marche, Dept Pediat, Ancona, Italy
[14] IRCSS Burlo Garofalo, Dept Pediat, Inst Child Hlth, I-34137 Trieste, Italy