[1] Univ Basel Hosp, CH-4031 Basel, Switzerland
[2] Univ Hosp, Kantonsspital Liestal, GI Unit, CH-4410 Liestal, Switzerland
[3] Univ Hamburg, Akad Lehrkrankenhaus, Israelit Krankenhaus, Hamburg, Germany
[4] Osped S Orsola Malpighi, Bologna, Italy
[5] Univ Leipzig, Leipzig, Germany
[6] Hop Adultes La Timone, Marseille, France
[7] Heidelberg Univ, Heidelberg, Germany
[8] Klinikum Stadt Hanau, Hanau, Germany
[9] Scarborough Gen Hosp, Scarborough, England