1. Department of Gastroenterology, Vitkovice Hospital, Czech Republic;
2. 2nd Department of Medicine, Faculty of Medicine and Dentistry, Palacky University Olomouc, Czech Republic;
3. Department of Medicine, Faculty of Medicine at Hradec Kralove, Charles University in Prague, Czech Republic;
4. Department of Surgery I, Faculty of Medicine and Dentistry, Palacky University Olomouc, Czech Republic;
5. Department of Gastroenterology and Hepatology, Klinikum Spandau, Berlin, Germany