Background and purpose: To screen for cancer and gastrointestinal bleeding, same-day bidirectional endoscopy, including esophagogastroduodenoscopy (EGD) and colonoscopy, is commonly done. However, the best order for the operations is yet unknown. Methods: We performed a systematic review and meta-analysis of randomized controlled trials that compared screening outcomes when colonoscopy was done before or after EGD. The primary outcome was overall detection rate. Secondary outcomes included cancer detection rates, polyp detection rates, and adverse events. Risk ratios (RRs) with 95% confidence intervals (CIs) were calculated using a random-effects model. Heterogeneity among studies was assessed using I2 statistics. A sensitivity analysis was conducted to assess the influence of each study on the summary effect. Results: Seven trials with 1,719 participants were included in this analysis. Overall detection rate was similar between groups (RR, 0.97; 95% CI, 0.88-1.06). Subgroup analyses showed no significant differences in detection rates by type of lesion or trial design. There was evidence of statistical heterogeneity among studies (I2 = 72%). Results were consistent in the sensitivity analysis. No serious adverse events were reported. Conclusions: Screening for colorectal cancer using bidirectional endoscopy appears to be effective and safe regardless of the order of procedures.