1. Department of Pediatrics, Gastroenterology and Nutrition, Faculty of Medicine, Jagiellonian University Medical College, Krakow, Poland.
2. Department of Pediatrics, Gastroenterology and Nutrition, University Chlildren's Hospital, Krakow, Poland.
3. Department of Health Promotion and e Health, Faculty of Health Sciences, Institute of Public Health, Jagiellonian University Medical College, Krakow, Poland.