Novel 1-L polyethylene glycol + ascorbate versus high-volume polyethylene glycol regimen for colonoscopy cleansing: a multicenter, randomized, phase IV study

Alessandro Repici, Cristiano Spada, Cristiano Spada, Renato Cannizzaro, Rino Cannizzaro, Mario Traina, Roberta Maselli, Stefania Maiero, Alessia Galtieri, Giovanni Guarnieri, Giorgia Guarnieri, Milena Di Leo, Mauro Di Leo, Roberto Lorenzetti, Antonio Capogreco, Marco Spadaccini, Giulio Antonelli, Angelo Zullo, Michele Amata, Elisa FerraraPaola Emilia Ferrara, Loredana Correale, Antonino Granata, Paola Cesaro, Franco Radaelli, Leonardo Minelli Grazioli, Andrea Anderloni, Alessandro Fugazza, Elena Finati, Gaia Pellegatta, Silvia Carrara, Pietro Occhipinti, Andrea Buda, Alessandro Buda, Lorenzo Fuccio, Mauro Manno, Cesare Hassan

Research output: Contribution to journalArticle


Background and Aims: Adequate bowel cleansing is critical to ensure quality and safety of a colonoscopy. A novel 1-L polyethylene glycol plus ascorbate (1L-PEG+ASC) regimen was previously validated against low-volume regimens but was never compared with high-volume regimens. Methods: In a phase IV study, patients undergoing colonoscopy were randomized 1:1 to receive split-dose 1L PEG+ASC or a split-dose 4-L PEG-based regimen (4L-PEG) in 5 Italian centers. Preparation was assessed with the Boston Bowel Preparation Scale (BBPS) by local endoscopists and centralized reading, both blinded to the randomization arm. The primary endpoint was noninferiority of 1L-PEG+ASC in colon cleansing. Secondary endpoints were superiority of 1L-PEG+ASC, patient compliance, segmental colon cleansing, adenoma detection rate, tolerability, and safety. Results: Three hundred eighty-eight patients (median age, 59.8 years) were randomized between January 2019 and October 2019: 195 to 1L-PEG+ASC and 193 to 4L-PEG. Noninferiority of 1L-PEG+ASC was demonstrated for cleansing in both the entire colon (BBPS ≥ 6: 97.9% vs 93%; relative risk [RR], 1.03; 95% confidence interval [CI], 1.001-1.04; P superiority = .027) and in the right-sided colon segment (98.4% vs 96.0%; RR, 1.02; 95% CI, .99-1.02; P noninferiority = .013). Compliance was higher with 1L-PEG+ASC than with 4L-PEG (178/192 [92.7%] vs 154/190 patients [81.1%]; RR, 1.10; 95% CI, 1.05-1.12), whereas no difference was found regarding safety (moderate/severe side effects: 20.8% vs 25.8%; P = .253). No difference in adenoma detection rate (38.8% vs 43.0%) was found. Conclusions: One-liter PEG+ASC showed noninferiority compared with 4L-PEG in achieving adequate colon cleansing and provided a higher patient compliance. No differences in tolerability and safety were detected. (Clinical trial registration number: NCT03742232.)
Original languageEnglish
Pages (from-to)823-831
Number of pages9
JournalGastrointestinal Endoscopy
Publication statusPublished - 2021


  • high-volume polyethylene glycol


Dive into the research topics of 'Novel 1-L polyethylene glycol + ascorbate versus high-volume polyethylene glycol regimen for colonoscopy cleansing: a multicenter, randomized, phase IV study'. Together they form a unique fingerprint.

Cite this