1. Gastroenterology and Endoscopy Unit; Fondazione IRCCS Cà Granda Ospedale Maggiore Policlinico; Milano Italy
2. NIHR Nottingham Biomedical Research Centre (BRC), Nottingham University Hospitals NHS Trust and the University of Nottingham; Nottingham UK
3. School of Medicine; Nottingham Digestive Diseases Centre, University of Nottingham; Nottingham UK