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

BACKGROUND: Bowel 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-liter polyethylene glycol (PEG) solution containing ascorbic acid has been recently developed. AIMS: To compare the efficacy, safety and acceptability of 2-liter PEG + ascorbic acid vs 4- liter PEG for colonoscopy. METHODS: We designed a single blind randomized non-inferiority study in order to compare the two bowel preparation. 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. RESULTS: Overall, 169 patients (PP: 166) were selected for the 2-liter PEG + ascorbic acid and 170 (PP: 166) for the 4-liter 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-liter PEG + ascorbic acid and 75.3% (PP: 77%) of patients who received 4-liter PEG (p= 0.04). Acceptability rate favoured 2-Liter PEG + ascorbic acid vs 4-Liter PEG (83% vs 76%; p= 0.02). CONCLUSIONS: 2-liter PEG + ascorbic acid, completed with an additional liter of clear fluids, provided a bowel cleansing appeared to be more effective and acceptable than 4-Liter PEG.