S703 Behind the Prep: Sex and BMI as Independent Predictors of Suboptimal Bowel Cleansing in EMR Patients

Introduction: Effective detection and resection of precancerous polyps is critical to reducing colorectal cancer (CRC)-related morbidity and mortality. A meta-analysis of 8 surveillance studies found that nearly 50% of post-colonoscopy CRCs were due to missed lesions and about 20% to incomplete resection. Endoscopic mucosal resection (EMR) is a widely used technique for resecting large polyps (>20 mm), which often require piecemeal resection, and are significantly more likely to harbor submucosal invasive cancer. Adequate bowel preparation is essential for optimal visualization during colonoscopy, impacting adenoma detection and complete resection rates. This study sought to identify demographic determinants associated with suboptimal bowel preparation in patients undergoing EMR. Methods: A retrospective chart review of 384 patients undergoing EMR was conducted at a large academic medical center from June 2016 to June 2022. Demographic data and bowel preparation quality were assessed. Preparation quality was recorded as inadequate or adequate according to Boston Bowel Preparation Score (BBPS). Inadequate preparation was defined as a BBPS score less than 6. Patients were classified as non-obese (body mass index [BMI] <30) or obese (BMI ≥30). Chi-square and logistic regression analysis were used for categorical variable comparisons. Results: Male sex significantly increased the probability of inadequate preparation (odds ratio [OR] 1.93; 95% CI, 1.26-2.96; P = 0.0024). Additionally, obese patients had a higher likelihood of suboptimal preparation relative to non-obese patients (OR 1.69; 95% CI, 1.11-2.58; P = 0.014). Obese men had nearly 2 times higher odds of inadequate preparation compared to non-obese women (OR 1.98; 95% CI, 1.08-3.62; P = 0.027) and obese women (OR 1.92; 95% CI, 1.02-3.63; P = 0.045). Average polyp size was 23 mm. 93.3% of polyps were completely resected. 3.6% of polyps were removed en bloc. Conclusion: Our findings suggest that male sex and obesity are independently associated with a higher likelihood of inadequate bowel preparation, potentially reflecting broader patterns in comorbidity burden. Male sex alone was a predictor for inadequate preparation, with men being 1.9 times more likely to have poor preparation. Similarly, obese patients were 1.7 times more likely to have poor preparation compared to non-obese individuals, with the highest risk being observed in obese men (OR 1.98). Identifying patients at higher risk for suboptimal preparation can inform more aggressive or tailored bowel cleansing protocols.