Bowel preparation quality between hospitalized patients and outpatient colonoscopies

Background/Aims: Optimal bowel preparation is essential for a complete high-quality colonoscopy. We sought to determine whether an inpatient, as opposed to an ambulatory setting, would affect the quality of bowel preparation. Patients and Methods: A retrospective chart review was conducted in a tertiary care university hospital. We collected demographic data from consecutive patients who underwent a colonoscopy for any reason between August 2007 and April 2012. Results: A total of 2999 patients were included in the study with a mean age of 50.36 (95% CI; 49.79-50.94). Males comprised 58.12%. Ambulatory patients had a higher rate of good bowel preparations (67.23% vs. 56.64%, P value < 0.01), a lower rate of poor bowel preparations (18.22% vs. 27.14%, P value < 0.01), and a higher rate of colonoscopy completion (86.79% vs. 77.59%, P value < 0.01). There was no difference between the rates of polyps detected (18.90% vs. 20.83%, P value = 0.22). The univariabe modeling factors associated with a sub-optimal bowel preparation were age OR 1.02 (95% CI, 1.01 to 1.02), chronic kidney disease OR 2.34 (95% CI, 1.12 to 4.88), diabetes mellitus OR 2.00 (95% CI, 1.50 to 2.68), hypertension OR 1.48 (95% CI, 1.11 to 1.97), anemia OR 1.81 (95% CI, 1.33 to 2.47), and weight loss OR 1.41 (95% CI, 1.01 to 1.96). Better bowel preparation was associated with colonoscopies performed in the outpatient setting OR 0.63 (95% CI, 0.54 to 0.73). Conclusion: Bowel preparation quality is affected by the setting in which it is performed. This result suggests that, when appropriate, colonoscopies should be performed on an outpatient basis. Further studies are required to replicate this finding.