1. Inflammatory Bowel Disease Center, Department of Gastroenterology, Radboud University Medical Center , Nijmegen , The Netherlands
2. Division of Gastroenterology, Department of Medicine, University of Alberta , Edmonton, AB , Canada
3. Ottawa Hospital IBD Center and Department of Medicine, University of Ottawa , Ottawa, ON , Canada
4. University of Chicago Medicine Inflammatory Bowel Disease Center, University of Chicago , Chicago, IL , USA
5. Division of Gastroenterology, Department of Medicine, McGill University Health Center , Montreal, QC , Canada
6. Department of Pathology, Radboud University Medical Center , Nijmegen , The Netherlands
7. Department of Surgery, Amsterdam University Medical Center , AMC , Amsterdam , The Netherlands
8. Department of Gastroenterology, Erasmus Medical Center , Rotterdam , The Netherlands