[1] John Radcliffe Hosp, Oxford OX3 9DU, England
[2] Univ Roma Tor Vergata, Dipartimento Med Interna, Cattedra Gastroenterol, I-00133 Rome, Italy
[3] Goethe Univ Frankfurt, Acad Teaching Hosp, Markus Hosp, Head Dept Med 1, D-60431 Frankfurt, Germany
[4] Sophia Childrens Univ Hosp, Erasmus MC, Rotterdam, Netherlands
[5] Univ Coll London Hosp, Dept Gastroenterol, London NW1 2BU, England
[6] Univ Bologna, Policlin S Orsola, Dept Internal Med & Gastroenterol, I-40126 Bologna, Italy
[7] St Marien Hosp, Med Klin 1, D-67067 Ludwigshafen, Germany
[8] Univ Klinikum Schleswig Holstein, Klin Psychosomat & Psychotherapie, D-23538 Lubeck, Germany
[9] Johannes Gutenberg Univ Mainz, Med Clin 1, Mainz, Germany
[10] Univ Zagreb, Childrens Hosp, Zagreb 10000, Croatia
[11] CHU Vaudois, Div Gastroenterol & Hepatol, Lausanne, Switzerland
[12] European Federat Crohns & Ulcerat Colitis Assoc, Bournemouth BH11 9TY, Dorset, England
[13] Univ Hosp Vienna, Dept Internal Med 4, A-1090 Vienna, Austria
[14] Hosp Clin Barcelona, Inflammatory Bowel Dis Unit, Barcelona 08036, Spain
[15] Linkoping Univ Hosp, Dept Surg, SE-58185 Linkoping, Sweden
[16] Robert Bosch Krankenhaus, Innere Med Abt 1, Schwerpunkte Gastroenterol Hepatol & Endokrinol, D-70341 Stuttgart, Germany
[17] Univ Zagreb, Univ Hosp Rebro, Div Gastroenterol & Hepatol, Zagreb 10000, Croatia