1 Department of Gastroenterology, University Hospital Augsburg, Germany. Electronic address: helmut.messmann@uk-augsburg.de.
2 Department of Gastroenterology, University Hospital Augsburg, Germany.
3 Humanitas University, Department of Biomedical Sciences, Pieve Emanuele, Italy; Humanitas Clinical and Research Center -IRCCS-, Endoscopy Unit, Rozzano, Italy.
4 Clinical Effectiveness Research Group, University of Oslo, Oslo, Norway; Digestive Disease Center, Showa University Northern Yokohama Hospital, Yokohama, Japan.