1 Centre for Academic Primary Care, Population Health Sciences, Bristol Medical School, University of Bristol, Bristol.
2 NIHR Applied Research Collaboration (ARC) West; Population Health Sciences, Bristol Medical School, University of Bristol, Bristol.
3 NIHR ARC West; Population Health Sciences, Bristol Medical School, University of Bristol, Bristol.
4 Patient representative, Bristol.
5 Academic Unit of Gastroenterology, Sheffield Teaching Hospitals; Division of Clinical Medicine, School of Medicine and Population Health, University of Sheffield, Sheffield.