Incidence and predicting factors of inadequate bowel preparation for colonoscopy: A cross-sectional study

Adequate bowel preparation is necessary for optimal colonoscopy. Inadequate bowel preparation results in increased costs and imprecise colonoscopy results. This study aims to determine the incidence and risk factors of inadequate bowel preparation.

In this study, 604 consecutive patients were observed prospectively who underwent colonoscopy examination. The patient's clinical and demographic data were obtained on the day of the procedure. Bowel preparation was evaluated by Boston Bowel Preparation Scale (BBPS) and was divided into two groups; adequate and inadequate. Univariate and multivariate analyses were performed.

Inadequate bowel preparation incidence was 17.9%. In the univariate analysis, education level (P value = 0.009), body mass index (P value = 0.03), admission type (P value = 0.038), previous history of colonoscopy (P value = 0.03), color and consistency of the last feces (P value = 0.03), diabetes (P value = 0.004), and smoking (P value = 0.03) were significantly related with the incidence of inadequate bowel preparation. While ischemic heart disease (IHD) decreased the level of inadequate bowel preparation (P value = 0.047). Multivariate analysis showed that diabetes mellitus (odds ratio [OR] = 2.18), smoking (OR = 2.10), inpatient status of admission type (OR = 3.32), last stool that was non-watery (OR = 1.60), and ischemic heart disease (OR = 0.032) were independent factors associated with inadequate bowel preparation.

Diabetic patients, smokers, inpatients and who defecated a non-watery and colory stool as the last defecation are at risk of inadequate bowel preparation and need more potent regimens. It is important to inform patients about preventable factors that affect bowel preparation to improve their preparation outcomes.