1. Department of Clinical Science, Intervention and Technology (CLINTEC), Karolinska Institutet and Center for Digestive Diseases, Karolinska University Hospital, Stockholm, Sweden
2. Digestive Diseases Centre, Vítkovice Hospital, Ostrava, Czech Republic
3. Digestive and Liver Disease Unit, Sant’Andrea Hospital, Sapienza University of Rome, Faculty of Medicine and Psychology, Rome, Italy