Quality of Bowel Preparation in the General Population

Background and Objectives: Colorectal cancer caused over 1.9 million new cases and 0.9 million deaths in 2020, ranking third in incidence and second in cancer mortality worldwide. Poor bowel preparation may hide adenomas, increasing the colorectal cancer risk. This retrospective study aims to identify differences and associations in bowel preparation quality in relation to gender, age, timing of preparation, and the type of cleansing agent used. Materials and Methods: We analyzed the quality of bowel preparation in a total of 4609 colonoscopies performed between June 2019 and April 2022. We used t-tests and ANOVA to assess differences in bowel preparation quality according to participants' characteristics. The multivariable linear and logistic regression analyses were used to evaluate the association between bowel preparation quality, withdrawal time, adequate bowel preparation, and total colonoscopy. Results: 70.9% of patients had adequate bowel preparation quality. Enema (β = -0.20, p < 0.001), bisacodyl (β = -0.16, p < 0.001), and senna solution (β = -0.03, p = 0.012) were linked to poorer bowel preparation quality in comparison with polyethylene glycol. Older age was associated with a slight decrease in the probability of adequate bowel preparation (adjusted OR 0.98 per year, p < 0.001), whereas female gender was associated with an increase in this probability (OR 1.18, p = 0.038). Bowel preparation in winter is associated with a lower likelihood of adequate preparation compared to summer (OR 0.74, p = 0.004). The type of bowel preparation agent affected outcomes, with enema (OR 0.22, p < 0.001) and bisacodyl (OR 0.35, p < 0.001) associated with the less clean bowels. Longer withdrawal time was inversely associated with adequate preparation (OR 0.94, p < 0.001). For total colonoscopy, the strongest predictor was adequate bowel preparation (OR 23.6, p < 0.001), with gender, ulcerative colitis, and polyps also influencing the outcome. Conclusions: Age, gender, season, medications, withdrawal time, and the type of colorectal lesions influence bowel preparation quality. Personalized approaches, including patient education and targeted interventions, might contribute to improved bowel preparation, especially in older patients, and should be evaluated in future studies.