1. Centre for Trauma and Surgery, and GI Physiology Unit, Barts and the London School of Medicine and Dentistry; Queen Mary University of London; London UK
2. Proctology Unit; Fondazione Policlinico Universitario A. Gemelli IRCCS; Rome Italy
3. Department of Econometrics, Statistics and Applied Economics; Riskcenter - IREA; Universitat de Barcelona; Barcelona Spain
4. Department of Gastroenterology and Hepatology; University Hospital Zurich; Zurich Switzerland
5. Centre for Medical Imaging; University College London; London UK