1. 2nd Department of General Surgery, Jagiellonian University Medical College, 31-066 Kraków, Poland
2. Department of Medical Education, Jagiellonian University Medical College, 31-066 Krakow, Poland
3. Department of Physiology, Faculty of Medical Sciences in Zabrze, Medical University of Silesia, 41-808 Zabrze, Poland
4. Department of Medical Statistic, Faculty of Pharmaceutical Sciences in Sosnowiec, Medical University of Silesia, 40-055 Sosnowiec, Poland
5. Department of General Surgery and Surgical Oncology, Ludwik Rydygier Memorial Hospital, 31-826 Kraków, Poland
6. Faculty of Medicine, Jagiellonian University Medical College, 31-066 Kraków, Poland
7. Department of Diagnostics, University Hospital, 30-688 Kraków, Poland
8. Department of Internal Medicine and Geriatrics, Faculty of Medicine, Jagiellonian University Medical College, 31-066 Krakow, Poland
9. Department of Endoscopy, University Hospital in Kraków, 30-688 Krakow, Poland