1. Cognitive Neurophysiology, Department of Child and Adolescent Psychiatry, Faculty of Medicine of the TU Dresden, Germany
2. Department of Medicine II, Justus-Liebig University Giessen, Germany
3. Department of Medicine I, University of Erlangen-Nuremberg, Erlangen, Germany
4. Berlin Institute of Health (BIH), Clinical Research Unit (CRU) – Biostatistics, Berlin, Germany
5. Institute of Biometry and Clinical Epidemiology (iBikE), Charité – Universitätsmedizin Berlin AND Berlin Institute of Health (BIH), Berlin, Germany
6. Institute for Social Medicine and Epidemiology, University of Lübeck, Germany
7. University of Rostock, Clinic for Psychosomatics and Psychotherapic Medicine, Rostock, Germany
8. Psychotherapy practice with focus on IBD, Hamburg, Germany
9. Gastroenterological practice, Kassel, Germany
10. Gastroenterological practice, Heidelberg, Germany
11. Gastroenterological practice, Lüneburg, Germany
12. Department of Gastroenterology, University Hospital of Schleswig-Holstein, Campus Lübeck, Lübeck, Germany and Gastroenterological Practice, Lübeck, Germany
13. Specialized Medical Center, Hagen, Germany
14. Center of Visceral Medicine, Gastroenterology, Endoscopy and Surgery, Justus-Liebig University Giessen, Giessen, Germany
15. Gastroenterological Practice, Herne, Germany
16. Municipal Clinic of Landau i.d. Pfalz, Germany
17. Gastroenterological Practice, Plauen, Germany
18. Gastroenterological Practice, Moessingen, Germany
19. Gastroenterological Practice, Leipzig, Germany
20. Charité – Universitätsmedizin Berlin, Campus Benjamin Franklin, Medical Clinic I, Berlin, Germany
21. Outpatient’s Department of Gastroenterology, University Teaching Hospital Lüneburg, Lüneburg, Germany
22. Gastroenterological practice, Minden
23. University Hospital of Schleswig-Holstein, Campus Kiel, Medical Clinic I, Kiel, Germany
24. Department of Gastroenterology and Hepatology. Charité Medical School, Humboldt-University, Berlin, Germany
25. Division of Gastroenterology, University of Alberta, Edmonton, AB, Canada
26. Department of Gastroenterology and Infectiology, Helios Clinic, Schwerin, Germany