Effectiveness of very low-volume preparation for colonoscopy: A prospective, multicenter observational study

BACKGROUND: The effectiveness of colonoscopy strictly depends on adequate bowel cleansing. Recently, a 1 L polyethylene glycol plus ascorbate (PEG-ASC) solution (Plenvu; Norgine, Harefield, United Kingdom) has been introduced on the evidence of three phase-3 randomized controlled trials, but it had never been tested in the real-life. AIM: To assess the effectiveness and tolerability of the 1 L preparation compared to 4 L and 2 L- PEG solutions in a real-life setting. METHODS: All patients undergoing a screening or diagnostic colonoscopy after a 4, 2 or 1 L PEG preparation, were consecutively enrolled in 5 Italian centers from September 2018 to February 2019. The primary endpoints of the study were the assessment of bowel cleansing success and high-quality cleansing of the right colon. The secondary endpoints were the evaluation of tolerability, adherence and safety of the different bowel preparations. Bowel cleansing was assessed through the Boston Bowel Preparation Scale. Adherence was defined as consumption of at least 75% of each dose, while tolerability was evaluated through a semi-quantitative scale. Safety was systematically monitored through adverse events reporting. RESULTS: Overall, 1289 met the inclusion criteria and were enrolled in the study. Of these, 490 patients performed a 4 L-PEG preparation (Selgesse(®)), 566 a 2 L-PEG cleansing (Moviprep(®) or Clensia(®)) and 233 a 1 L-PEG preparation (Plenvu(®)). Bowel cleansing by Boston Bowel Preparation Scale was 6.5 ± 1.5 overall and 6.3 ± 1.5, 6.2 ± 1.5, 7.3 ± 1.5 (P < 0.001) in the subgroups of 4 L, 2 L and 1 L-PEG preparation, respectively. Cleansing success was achieved in 72.4%, 74.1% and 90.1% (P < 0.001), while a high-quality cleansing of the right colon in 15.9%, 12.0% and 41.4% (P < 0.001) for 4 L, 2 L and 1 L-PEG preparation groups, respectively. The 1 L preparation was the most tolerated compared to the 2 and 4 L-PEG solutions in the absence of serious adverse events within any of the three groups. Multiple regression models confirmed 1 L PEG-ASC preparation as an independent predictor of overall cleansing success, high-quality cleansing of the right colon and of tolerability. CONCLUSION: This study supports the effectiveness and tolerability of 1 L PEG-ASC, also showing it is an independent predictor of overall cleansing success, high-quality cleansing of the right colon and of tolerability.