[1] Univ Roma La Sapienza, Dept Clin Sci, Rome, Italy
[2] Hosp Badalona Germans Trias & Pujol, Dept Gastroenterol & Hepatol, Badalona, Spain
[3] Univ Med Ctr, Erasmus MC Sophia Childrens Hosp, Rotterdam, Netherlands
[4] Univ Hosp Vienna, Dept Internal Med 4, Vienna, Austria
[5] Univ Copenhagen, Herlev Hosp, DK-2730 Herlev, Denmark
[6] UCL Hosp, London, England
[7] Univ Amsterdam, Acad Med Ctr, Dept Gastroenterol & Hepatol, NL-1105 AZ Amsterdam, Netherlands
[8] Humboldt Univ, Clin Gen Visceral Vasc & Thorac Surg, Berlin, Germany
[9] Univ Rome, Policlin Umberto I, Dept Clin Sci, GI Unit, Rome, Italy
[10] Univ Roma La Sapienza, Gastroenterol Unit, Rome, Italy
[11] Univ Zagreb, Univ Hosp Rebro, Div Gastroenterol & Hepatol, Zagreb, Croatia
[12] Astrid Lindgren Childrens Hosp, Dept Women & Child Hlth, Stockholm, Sweden
[13] Univ Zagreb, Childrens Hosp, Dept Gastroenterol & Nutr, Zagreb, Croatia
[14] Charles Univ Hosp, Dept Med 4, Prague, Czech Republic
[15] Cattedra Gastroenterol Policlin, Ist Med Interna, Milan, Italy
[16] Royal Free Hosp, Dept Gastroenterol, London NW3 2QG, England
[17] Stadtkrankenhaus Neuwied, Neuwied, Germany
[18] CHU Vaudois, Div Gastroenterol, Lausanne, Switzerland
[19] Adelaide & Meath Hosp, Dept Gastroenterol, Dublin, Ireland
[20] Hosp Garcia de Orta, Dept Gastroenterol & Hepatol, Almada, Portugal
[21] Univ Hosp, Dept Gastroenterol, Iraklion, Greece
[22] Heilig Hartziekenhuis, Roeselare, Belgium
[23] EFFCA, Bournemouth, Dorset, England
[24] Univ Nottingham Hosp, Wolfson Digest Dis Ctr, Nottingham, England