1. Department of Gastroenterology & HepatologyLeiden University Medical CenterLeidenThe Netherlands
2. Department of Gastroenterology & HepatologyUniversity Medical Center GroningenGroningenThe Netherlands
3. Department of Gastroenterology & HepatologyRadboud University Medical CenterNijmegenThe Netherlands
4. Department of Gastroenterology & HepatologyIsala ClinicsZwolleThe Netherlands
5. Department of Gastroenterology & HepatologyAcademic Medical CenterAmsterdamThe Netherlands
6. Department of SurgeryGelre HospitalsApeldoornThe Netherlands