Effect of acuity level and patient characteristics on bowel preparation quality: a retrospective cohort study of inpatient colonoscopies

Colonoscopy is the primary method to detect mucosal abnormalities in the colon, rectum, and terminal ileum. Inadequate bowel preparation is a common problem and can impede successful visualization during colonoscopy. Although studies identified hospitalization as a predictor of inadequate bowel preparation, acuity of care vary greatly within this patient population. The current study aims to examine the effect of patient characteristics and care level predictors on inadequate bowel preparation quality within the inpatient setting. This retrospective study was conducted in a single urban level 1 trauma medical center and included adult patients undergoing diagnostic colonoscopy while admitted in the hospital from January 1, 2015 to June 30, 2020. We examined the level of inpatient care between the General Medical Floor (GMF), Intensive Care Units (ICU) and Telemetry Unit (TU) and assessed this association with bowel preparation quality, adjusting for known and unknown predictors. Of 538 patients undergoing colonoscopy, 47.4% were admitted into TU, 43.7% into GMF and 8.9% into ICU. For the entire sample, 72.7% of patients achieved good or excellent preparation and quality of bowel preparation differed by care level (P = 0.01). Patients from the critical care units were less likely to achieve adequate bowel preparation when compared to GMF (Odds Ratio [OR] 0.36; 95% Confidence Interval [CI] 0.17,0.77), after adjusting for patient characteristics, medications, physical status, and preparation regimen. No significant difference in Bowel Preparation Quality (BPQ) was identified between patients from GMF and TU (OR 0.96; 95%CI 0.61, 1.52). Furthermore, adequate BPQ was associated with withdrawal time and cecal intubation, but not higher adenoma detection rates. Results suggest the ICU setting is an independent predictor for inadequate bowel preparation and patients with prior opioid and laxative use may be more likely to have inadequate bowel preparation in the hospital. Future interventions should prioritize preprocedural clinician meetings for critical care unit patients, including a more detailed readiness assessment and thorough medication history.