A randomized controlled trial evaluating a new 2-L PEG solution plus ascorbic acid vs 4-L PEG for bowel cleansing prior to colonoscopy

BackgroundBowel preparation is critical for the efficacy and safety of colonoscopy. Poor patient tolerance to bowel preparation has been associated with the high amount of fluid administered. A 2-L polyethylene glycol (PEG) solution containing ascorbic acid has been recently developed.AimsTo compare the efficacy, safety and acceptability of 2-L PEG + ascorbic acid vs 4-L PEG for colonoscopy.MethodsWe designed a single blind randomized non-inferiority study in order to compare the two bowel preparations. A blinded assessment of cleansing was made by the endoscopist according to the Aronchick scale. Acceptability was assessed by questionnaire. Intention-to-treat (ITT) and per-protocol (PP) analysis were reported.ResultsOverall, 169 patients (PP: 166) were selected for the 2-L PEG + ascorbic acid and 170 (PP: 166) for the 4-L PEG. When rating global bowel cleansing at ITT, an excellent-good level was reported in 84.6% (PP: 86.2%) of patients who received 2-L PEG + ascorbic acid and 75.3% (PP: 77%) of patients who received 4-L PEG (p = 0.04). Acceptability rate favoured 2-L PEG + ascorbic acid vs 4-L PEG (83% vs 76%; p = 0.02).Conclusions2-L PEG + ascorbic acid, completed with an additional L of clear fluids, provided bowel cleansing which appeared to be more effective and acceptable than 4-L PEG.