1. Department of Gastroenterology, General Hospital Celje, Celje
2. Department of Gastroenterology, University Medical Centre Ljubljana
3. Department of Internal Medicine, Faculty of Medicine, University of Ljubljana, Ljubljana
4. In-Medico, Department of Research and Development, Metlika, Slovenia
5. Faculty of Medicine, University of Ljubljana
6. Department of Abdominal Surgery, University Medical Centre Ljubljana
7. Department of Surgery, Faculty of Medicine, University of Ljubljana, Ljubljana
8. Department of Gastroenterology, General Hospital Jesenice, Jesenice
9. Department of Gastroenterology, University Medical Centre Maribor, Maribor
10. Department of Gastroenterology, General Hospital Izola, Izola
11. Diagnostic Centre Bled, Bled, Slovenia