[1] Univ Pisa, Dept Translat Res & New Technol Med & Surg, Gastroenterol Unit, Via Roma 67, I-56124 Pisa, PI, Italy
[2] Univ Padua, Dept Surg Oncol & Gastroenterol, Div Gastroenterol, Padua, Italy
[3] Pediat Inst Italian Switzerland, Bellinzona, Switzerland
[4] Univ Campania, Dept Surg, Div Surg, Naples, Italy
[5] Baggiovara Hosp, Gastroenterol Digest Pathophysiol Unit, Modena, Italy
[6] Univ Genoa, Dept Internal Med, Gastroenterol Unit, Genoa, Italy
[7] Univ Pisa, Dept Clin & Expt Med, Pediat Unit, Pisa, Italy