Background: High-quality bowel preparation is essential for successful outpatient colonoscopy. Currently, the rate of adequate bowel preparation for outpatient colonoscopy in the USA is low. Patients often fail to adhere to recommended preparation instructions. Limited literature exists on evaluating educational intervention as a means of improving the quality of bowel preparation prior to outpatient colonoscopy.
Objective: Our objective was to determine the effect of an educational intervention on the quality of outpatient colonoscopy preparation. The secondary objective was to determine whether the quality of bowel preparation improves overall colonoscopy outcomes as measured by rate of polyp detection and caecal intubation time.
Methods: A single-blinded, prospective, randomised, controlled trial was conducted in two inner-city gastroenterology clinics in the USA. One hundred and sixty-four subjects were enrolled and randomly assigned to one of two groups. The control group subjects received verbal and written instructions for colonoscopy. The intervention group subjects received the same instructions and were then asked to answer a questionnaire. The subjects' responses were reviewed and an additional explanation of the preparation process provided. An attending gastroenterologist determined the quality of each bowel preparation at the time of colonoscopy using the Universal Preparation Assessment Scale.
Results: The educational intervention had no impact on the overall quality of bowel preparation (P=0.12). However, the type of food (liquid vs solid) consumed during the 24 hours prior to the procedure (P=0.04) and the time since the last solid meal (P=0.03) did have an impact on preparation quality. Other significant factors included elapsed time to first bowel movement from the initiation of bowel preparation (P=0.05) and age younger than 55 (P=0.02). Adequate bowel preparation was associated with shorter total procedure (P=0.001) and caecal intubation (P=0.01) times.
Conclusion: Our study failed to demonstrate any effect of an educational intervention on the quality of colonoscopy preparation. However, adherence to simple dietary instructions did have a significant impact on the quality of bowel preparation. Adequate bowel preparation was associated with shorter procedure time and caecal intubation time.