BackgroundTraditional preoperative reminding services were applied to enhance the quality of bowel preparation. However, their effects might be affected. In this study, we proposed to use automated Electronic reminder system (E‐reminder) and validated its effectiveness on improving bowel preparation and the quality of preoperative education before colonoscopy.MethodsDuring August 2021 to March 2022, we included 833 outpatients aged 50–75 who underwent colonoscopy, and all patient were randomly assigned after obtaining informed consent. The control group received routine preoperative education. The E‐reminder group received automatic phone‐calling, text message reminders and web services before the operation. The entire process of patient information registration and reminding services were automatically completed by E‐reminder. Finally, the effect of reminders were evaluated by Boston Bowel Preparation Scale (BBPS) score and the previously validated objective evaluation scale of automatic BBPS (eBBPS) .ResultsIn manual assessment, the rate of adequate bowel preparation was improved in E‐reminder group (60.7% vs 54.5%; P = 0.01). The percentage of objective evaluated adequate bowel preparation in the E‐reminder group was significantly higher than that in the control group (75.2% vs 69.2%; P = 0.02). In E‐reminder group, the rate of willingness to repeat bowel preparations (79.5% vs 71.9%, P = 0.02), and taking laxatives on time (100% vs 97.6%, p = 0.02) were higher than control group. In PP population, the polyp detection rate (PDR) showed a significant trend towards being higher in the E‐reminder group than in the control group (80.9% vs 73.8%, p = 0.03). The adenoma detection rate (ADR) showed a similar trend in the E‐reminder group and control group (15.9% vs 14.3%, p = 0.55).ConclusionE‐reminder was an effective tool to improve the quality of bowel preparation and compliance with medical instructions. It was potential to be an efficient and convenient education tool improving the quality of medical service.This article is protected by copyright. All rights reserved.