Comparison of morning versus afternoon cecal intubation rates

Background: Many factors impacting cecal intubation rates have been examined in detail; however, little information exists regarding the effect of the timing of the procedure. We sought to examine any difference in cecal intubation rates between morning and afternoon colonoscopies and identify factors contributing to a discrepancy. Methods: Retrospective, single-center study comparing cecal intubation rates for colonoscopies performed in the morning (begun prior to 12 noon) and colonoscopies performed in the afternoon (begun after 12 noon) over an approximately 12 month period. Univariate and multivariate analyses were performed evaluating patient demographics, procedure indication(s), endoscopist, bowel preparation type and quality, and participation by a gastroenterology fellow. Results: 6087 colonoscopies were evaluated in this study. Colonoscopies (n = 3729) performed in the morning were compared to colonoscopies performed in the afternoon (n = 2358). The crude completion rate to the cecum was 95.0% in the morning group while the completion rate to the cecum was 93.6% of the afternoon exams (p = 0.02). The morning colonoscopies had better bowel preparation quality (p < 0.001). The multivariate analyses demonstrated that gender, age, and bowel preparation quality impacted completion rates. After correcting for these factors, there was no significant difference in completion rates in the morning versus afternoon. Conclusion: Uncorrected cecal intubation rates were lower in the afternoon compared to the morning in outpatients undergoing colonoscopy. Bowel preparation quality was worse in the afternoon compared with the morning. Efforts at improving afternoon bowel preparation may improve the outcome of afternoon colonoscopies.