Ivica Grgurevic1, Nermin Salkic2, Anita Madir1, Gorana Aralica3. 1. Department of Gastroenterology, Hepatology and Clinical Nutrition, University Hospital Dubrava, University of Zagreb School of Medicine and Faculty of Pharmacy and Biochemistry, Zagreb, Croatia. 2. Department of Gastroenterology and Hepatology, University Hospital Centre Tuzla, Tuzla, Bosnia and Herzegovina. 3. Department of Pathology and Cytology, University Hospital Dubrava, University of Zagreb School of Medicine, Zagreb, Croatia.