[1] Hosp Univ Princesa, Dept Gastroenterol, Madrid, Spain
[2] Bridge Med Ctr, Crawley, W Sussex, England
[3] Athens Med Ctr, Dept Gastroenterol, Athens, Greece
[4] Haukeland Hosp, Inst Med, N-5021 Bergen, Norway
[5] Karolinska Inst, Ctr Family & Community Med, Huddinge, Sweden
[6] Klinikum Salzgitter GmbH, Salzgitter, Germany
[7] AstraZeneca, Madrid, Spain