1. Innere Abteilung Ev; Krankenhaus Kalk; University of Cologne; Köln; Germany
2. Private Gastroenterology Practice; Amberg; Germany
3. Private Gastroenterology Practice; Wolmirstedt; Germany
4. Private Gastroenterology Practice; Mannheim; Germany
5. Clinical Research & Development Department; Dr. Falk Pharma GmbH; Freiburg; Germany