Einar S Björnsson1,2. 1. Department of Internal Medicine, Division of Gastroenterology and Hepatology, Landspitali University Hospital, Hringbraut, Building H 101, Reykjavík, Iceland. einarsb@landspitali.is. 2. Faculty of Medicine, University of Iceland, Reykjavík, Iceland. einarsb@landspitali.is.