1 King's Health Partners Institute for Therapeutic Endoscopy, King's College Hospital, London, UK; Wolfson Unit for Endoscopy, St Mark's Hospital, London, UK. Electronic address: robin.baddeley2@nhs.net.
2 Department of Gastroenterology and Hepatology, Hospital Universitario Ramón y Cajal, Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Universidad de Alcalá, Madrid, Spain.
3 Department of Gastroenterology, Whipps Cross Hospital, Barts Health NHS Trust, London, UK.
4 Department of Digestive Diseases, Aberdeen Royal Infirmary, NHS Grampian, Aberdeen, UK.
5 School of Health and Life Sciences, Teesside University, Middlesbrough, UK; Department of Gastroenterology, County Durham and Darlington NHS Foundation Trust, Darlington, UK.
6 Wolfson Unit for Endoscopy, St Mark's Hospital, London, UK; Department of Metabolism, Digestion and Reproduction, Imperial College London, London, UK.
7 King's Health Partners Institute for Therapeutic Endoscopy, King's College Hospital, London, UK.