[1] South Tyneside NHS Fdn Trust, Dept Gastroenterol, South Shields NE34 0PL, England
[2] Univ Durham, Sch Med Pharm & Hlth, Durham, England
[3] Northern Reg Endoscopy Grp, London, England
[4] Imperial Coll, St Marks Hosp, Endoscopy Unit, London, England
[5] Univ Hosp North Tees, Dept Gastroenterol, Stockton On Tees, England
[6] Univ Hosp Coventry & Warwickshire NHS Trust, Coventry, W Midlands, England
[7] South Devon Healthcare NHS Fdn Trust, Torquay, England
[8] Royal Liverpool Univ Hosp, Liverpool, Merseyside, England