1. Department of Gastroenterology, Academic Medical Center, Amsterdam, the Netherlands
2. Department of Gastroenterology, AZ Delta, Roeselare, Belgium
3. Department of Gastroenterology, University Hospital Gasthuisberg, Leuven, Belgium
4. Department of Gastroenterology, AZ Groeninge, Kortrijk, Belgium
5. Department of Gastroenterology, Ghent University Hospital, Ghent, Belgium
6. Department of Medicine, UCLA Center for Inflammatory Bowel Diseases, Los Angeles, USA