1. Leeds Gastroenterology Institute; St. James's University Hospital; Leeds UK
2. Department of Clinical Medicine; S. Orsola Hospital Bologna; University of Bologna; Bologna Italy
3. Department of Gastroenterology; Instituto de Investigación Sanitaria Princesa (IP) and Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBEREHD); Hospital Universitario de la Princesa; Madrid Spain
4. Department of Gastroenterology; Tallaght Hospital/Trinity College Dublin; Dublin Ireland