1 Endoscopy Unit, Digestive Diseases Department, La Fe Polytechnic University Hospital, Gastrointestinal Endoscopy Research Group, IIS Hospital La Fe, Valencia, Spain.
2 Digestive Endoscopy Unit, Hospital Puerto Montt, Puerto Montt, Chile.
3 Departamento de Gastroenterología, Escuela de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile.
4 NIHR Nottingham Biomedical Research Centre, Nottingham University Hospitals NHS Trust, Nottingham, UK.
5 Nottingham Digestive Diseases Centre, The University of Nottingham, Nottingham, UK.