[1] Hosp Luneburg, Outpatients Dept Gastroenterol, Luneburg, Germany
[2] Herlev & Gentofte Univ Hosp, Gastroenterol Sect, Hellerup, Denmark
[3] Royal London Hosp, Dept Gastroenterol, London, England
[4] North Zealand Univ Hosp, Dept Gastroenterol, Frederikssund, Denmark
[5] Mater Dei Hosp, Dept Gastroenterol, Msida, Malta
[6] Hosp Alvaro Cunqueiro, Dept Gastroenterol, Vigo, Spain
[7] Gazi Univ, Fac Med, Dept Gastroenterol, Ankara, Besevler, Turkey
[8] Univ Ioannina, Dept Gastroenterol & Hepatol, Ioannina, Greece
[9] Med Sch Ioannina, Ioannina, Greece
[10] Pauls Stradins Clin Univ Hosp, Dept Gastroenterol Hepatol & Nutr Therapy, Riga, Latvia
[11] Tel Aviv Univ, Wolfson Med Ctr, Tel Aviv, Israel
[12] Evangelismos Med Ctr, Dept Gastroenterol, Athens, Greece
[13] Beacon Consultants Clin, Dept Gastroenterol, Dublin, Ireland
[14] Sodra Alvsborgs Hosp, Dept Internal Med, Boras, Sweden
[15] Izmir Katip Celebi Univ, Ataturk Teaching & Res Hosp, Dept Gastroenterol, Izmir, Turkey
[16] Univ Hosp Careggi, Div Gastroenterol, Florence, Italy