Dai 2010.

Methods	Generation of allocation sequence: Not stated. Allocation concealment: Not stated. Blinding: Not stated. Inclusion of all randomised patients: Not stated.
Participants	Number: 250 (134M:116F) Age: Cap group mean 49.4 years (range 22‐77). Regular group mean 53.3 years (range 18‐78). Source: Renji Hospital, Shanghai. Inclusion criteria: Patients undergoing outpatient colonoscopy. Exclusion criteria: Prior colonic surgery, IBD, colonic stricture or tumour, poor bowel preparation.
Interventions	Colonoscope: CF‐240 (Olympus, Tokyo, Japan). Bowel Preparation: 2L polyethylene glycol/electrolyte lavage solution (Shenzhen Wanhe, Shenzhen, China) 6hours before. Intra‐porcedure medication: 10mg Scopolamine, 10mg Diazepam I.M. Colonoscopists: 2 subgroups ‐ experienced (at least 5 years experience) and inexperienced (1 year experience). Caps: D‐201‐13404 (Olympus, Tokyo, Japan) transparent plastic cap: 13.7mm outer diameter, 11.7mm inner diameter, depth 8mm, protruding 4mm ahead of scope.
Outcomes	Included in review: Caecal intubation time, pain during procedure Excluded from review: Distension, total procedure time.
Notes	Location: China Source of funding: Not stated Attempts to clarify information: Not required. Language of Publication: English
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Not stated
Allocation concealment (selection bias)	High risk	Not blinded to endoscopist
Blinding (performance bias and detection bias) All outcomes	High risk	Not stated but not blinded to endoscopist.
Incomplete outcome data (attrition bias) All outcomes	Low risk	All data appears complete.
Selective reporting (reporting bias)	Low risk	Appropriate outcomes reported.
Other bias	Unclear risk	Source of funding not stated.