A randomized, controlled trial of oral sulfate solution plus polyethylene glycol as a bowel preparation for colonoscopy

BackgroundNo bowel preparation for colonoscopy is optimal with regard to efficacy, safety, and tolerability. New options for bowel preparation are needed.ObjectiveTo compare a new hybrid preparation consisting of a reduced dose of oral sulfate solution (OSS) plus 2 L of sulfate-free electrolyte lavage solution (SF-ELS) with 2 low-volume preparations based on polyethylene glycol electrolyte lavage solution (PEG-ELS).DesignTwo randomized, controlled trials.SettingTwenty-four U.S. centers.PatientsA total of 737 outpatients undergoing colonoscopy.InterventionsIn study 1, OSS plus SF-ELS was given as a split dose, and in study 2, OSS plus SF-ELS was given in its entirety the evening before colonoscopy. In study 1, the active control was 2 L of PEG-ELS plus ascorbic acid (PEG-EA) given as a split dose. In study 2, the control was 10 mg of bisacodyl plus 2 L of SF-ELS taken the evening before colonoscopy.Main Outcome MeasurementsRates of successful (good or excellent) bowel preparation.ResultsIn study 1, the rates of successful (excellent or good) preparation with OSS plus SF-ELS and PEG-EA were identical at 93.5% for split-dose preparation. OSS plus SF-ELS was noninferior to PEG-EA (P < .001). In study 2, OSS plus SF-ELS resulted in successful preparation in 89.8% of patients compared with 83.5% with bisacodyl plus SF-ELS in a same-day preparation regimen. OSS plus SF-ELS was noninferior to bisacodyl plus SF-ELS (P <.001). In study 1, vomiting was more frequent with OSS plus SF-ELS (13.5% vs 6.7%; P = .042), and bloating was rated worse with PEG-EA (P = .025). In study 2, overall discomfort was rated worse with OSS plus SF-ELS (mean score 2.1 vs 1.8; P = .032). There were no deaths in either study and no serious adverse events considered related to the preparation.LimitationsBowel cleansing was not scored by colon segment. Adenoma detection was not compared between the regimens.ConclusionOSS plus SF-ELS is a new, safe, and effective bowel preparation for colonoscopy.