Split dose bowel preparation before colonoscopy of PEG (Nulytely) in comparison to routine single dose bowel preparation.

Background: The aim of this study was to compare the efficacy and tolerability of polyethylene glycol (PEG) in single- or split-dose regimens for colonoscopy bowel preparation. Methods: This is a prospective, randomized, endoscopist blinded, single-center study, that included adult patients who underwent colonoscopy during the period from December 2017 to October 2018. Two groups were enrolled in the same period: One group used 4 L of PEG (Nulytely) in a single-dose preparation, administered a day before the procedure, and the other group received a split-dose regimen of 2 L PEG (Nulytely), given a day before the procedure and 2 L on the day of the procedure in the early morning. The Boston Bowel Preparation Scale (BBPS) was used for bowel preparation adequacy; scales 0 and 1 were considered inadequate, and scales 2 and 3 were considered adequate preparation. Results: Two hundred and forty patients were enrolled, 120 (50%) using the split-dose regimen and 120 (50%) using the single-dose regimen, for bowel preparation. Males constituted 51.6% of the study cohort. In the single-dose group, 62.5% achieved adequate bowel preparation compared to 89.2% in the split-dose group (p< 0.001). In addition, polyp detection in the split-dose group was 23.3% in comparison to 10.8% in the single-dose group (P = 0.016). We also found hypertension and diabetes as significant predictors of bowel preparation inadequacy, while sex and age were not related to bowel preparation adequacy. Conclusions: Split-dose bowel preparation for colonoscopy with PEG (Nulytely) is better than routine single-dose, in terms of adequate bowel preparation and polyp detection.