Multimodal patient education improves bowel preparation for colonoscopy: a randomized controlled trial

Inadequate bowel preparation (BP) compromises colonoscopy quality, efficiency, and patient outcomes. We evaluated whether a resource-light multimodal educational package improves BP adequacy compared with standard instructions. We conducted a prospective, single-blinded, parallel-group, single-center randomized clinical trial in which adults scheduled for elective colonoscopy were randomized 1:1 to standard education (leaflet) or enhanced education (face-to-face counseling, 6-minute video, illustrated booklet, smartphone-app reminders). The primary outcome was adequate preparation, defined as a composite criterion of total Boston Bowel Preparation Scale (BBPS) ≥ 6 with all three colonic segments (right, transverse, left) scoring ≥ 2. Secondary outcomes included total BBPS ≥ 6 irrespective of segment scores, segmental BBPS ≥ 2, mean segmental and total BBPS, cecal intubation success and times, withdrawal time, adverse effects, compliance, anxiety, and satisfaction. Exploratory multivariable logistic regression examined clinical predictors of adequate BP. A total of 150 patients were analyzed (75 per group). Using the composite primary definition, adequate preparation was achieved in 60/75 (80.0%) in the intervention group versus 49/75 (65.3%) in controls (risk ratio [RR] 1.22; 95% CI 1.00–1.50; p = 0.047; number-needed-to-treat ≈ 7). For total BBPS ≥ 6 irrespective of segment scores, adequacy was 85.3% versus 70.7% (RR 1.21; 95% CI 1.02–1.44; p = 0.033). Segmental BBPS ≥ 2 favored the intervention in the left (90.7% vs. 78.7%; p = 0.044) and transverse colon (92.0% vs. 80.0%; p = 0.037), with a concordant but non-significant trend in the right colon. Mean total BBPS (6.79 ± 1.55 vs. 6.11 ± 1.72; p = 0.012) and mean right and transverse segment scores were also higher with the intervention, indicating a global shift toward better cleanliness. Cecal intubation success (98.7% in both groups), cecal intubation and withdrawal times, self-reported compliance, adverse effects, anxiety scores, and satisfaction did not differ meaningfully between groups. In exploratory adjusted analyses, the intervention remained positively associated with adequacy (adjusted odds ratio 1.89; 95% CI 0.86–4.26), and polypharmacy emerged as an independent negative predictor (0.42; 95% CI 0.18–0.96). A brief, low-cost multimodal education strategy improved bowel preparation quality, increasing the proportion of patients achieving guideline-relevant BBPS adequacy without adversely affecting patient experience or procedure times. Implementation in routine practice may help endoscopy units move closer to recommended quality benchmarks and reduce the burden of inadequate-prep–related repeat examinations. This clinical trial was registered on ClinicalTrials.gov (Identifier: NCT07093099). And was registered retrospectively on July 29, 2025, due to being the first RCT in our center and there was an administrative error in early registration, but IRB approval letters are available to confirm strict adherence to the original protocol. The Registration is available at https://clinicaltrials.gov/study/NCT07093099.