“…29 In nine 30,31,34,35,[39][40][41][42]45 of 21 included trials, a total of 125 participants were excluded after randomisation for insufficient bowel preparation, active colonic inflammation, short disease duration or lack of compliance with the study protocol. Fourteen trials [30][31][32]34,37,[39][40][41]43,44,[46][47][48][49] included only participants with ulcerative colitis, six trials 29,33,35,38,42,45 enrolled participants with both ulcerative colitis and Crohn's disease, and one trial included participants with ulcerative colitis, Crohn's disease and unclassified colitis. 36 Eight endoscopic techniques for dysplasia surveillance were evaluated: chromoendoscopy (13 trials), high definition white-light endoscopy (9 trials), narrow band imaging (8 trials), standard definition white-light endoscopy (6 trials), autofluorescence (3 trials), i-SCAN (2 trials), full spectrum high definition white-light endoscopy (Endochoice, Alpharetta, USA) (1 trial) and Fujinon intelligent colour enhancement FICE (Fujifilm, Tokyo, Japan) (1 trial).…”