Basic characteristics (such as age, sex, comorbidities, indication of colonoscopy, and measures for bowel preparation), quality indicators (the total examination time, adenoma detection rate (ADR), number of experienced endoscopists, cecal intubation rate (CIR)), and outcomes (such as adequate bowel preparation (ABP) rate, total and segments score of BBPS, tolerability, and complications) were extracted from the eligible articles by the two independent investigators (Xin Yuan and Lu Xu). The original data sets are presented in Table S2. Any discrepancies between the investigators were arbitrated and solved by mutual discussion, and reached an agreement with the assistance of a senior investigator (Lei Xu).