Combination of Enhanced Instructions Improve Quality of Bowel Preparation: A Prospective, Colonoscopist-Blinded, Randomized, Controlled Study

BACKGROUND: Appropriate bowel preparation is highly important for the efficacy of colonoscopy; however, up to one-third of patients do not accomplish adequate bowel preparation. OBJECTIVE: We investigated the impact of the combination of enhanced instruction on the quality of bowel preparation and its impact on clinically relevant outcomes. DESIGN: This was a colonoscopist-blinded, prospective, randomized trial. SETTINGS: All patients received regular instructions for bowel preparation. Patients were randomly assigned to the control, telephone reeducation, and combined enhanced instruction groups. PATIENTS: Outpatients aged 19 to 75 years scheduled to undergo colonoscopy were included. MAIN OUTCOME MEASURES: The main outcome was adequate bowel preparation rate. RESULTS: A total of 311 patients were randomly assigned to the combined enhanced instruction (n = 104), telephone reeducation (n = 101), and control groups (n = 106). An intention-to-treat analysis showed that the adequate bowel preparation rate was higher in the combined enhanced instruction group than in the telephone reeducation and control groups (92.3% vs 82.2% vs 76.4%, p = 0.007). The rate of compliance with the instructions was significantly higher in the combined enhanced instruction group than in the telephone reeducation and control groups. Method of education was associated with proper bowel preparation (adjusted OR 17.46; p < 0.001 for combined enhanced instruction relative to control). LIMITATIONS: This was a single-center study conducted in Korea. CONCLUSIONS: Combined enhanced instruction as an adjunct to regular instructions much improved the quality of bowel preparation and patients' adherence to the preparation instructions. The combined enhanced instruction method could be the best option for bowel preparation instruction.