Department of Gastroenterology and Hepatology, Radboud University Medical Centre, Nijmegen, The Netherlands. Department of Gastroenterology and Hepatology, Maastricht University Medical Centre, Maastricht, The Netherlands. Erasmus Medical Centre, Rotterdam, The Netherlands. Amphia Hospital, Breda, The Netherlands. University Medical Centre Groningen, University of Groningen, Groningen, The Netherlands. University Medical Centre Utrecht, Utrecht, The Netherlands. Amsterdam University Medical Centre, Academic Medical Centre, Amsterdam, The Netherlands. Zuyderland Medical Centre, Sittard, The Netherlands. Leiden University Medical Centre, Leiden, The Netherlands. Amsterdam University Medical Centre, Vrije Universiteit, Amsterdam Gastroenterology & Metabolism research institute, Amsterdam, The Netherlands. Haaglanden Medisch Centre, The Hague, The Netherlands. Franciscus Gasthuis & Vlietland, Rotterdam, The Netherlands. Jeroen Bosch Hospital, 's Hertogenbosch, The Netherlands. Rijnstate Hospital, Arnhem, The Netherlands. Onze Lieve Vrouwe Gasthuis, Amsterdam, The Netherlands.