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

Background: No bowel preparation for colonoscopy is optimal with regard to efficacy, safety, and tolerability. New options for bowel preparation are needed.

Objective: To 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).

Design: Two randomized, controlled trials.

Setting: Twenty-four U.S. centers.

Patients: A total of 737 outpatients undergoing colonoscopy.

Interventions: In 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 Measurements: Rates of successful (good or excellent) bowel preparation.

Results: In 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.

Limitations: Bowel cleansing was not scored by colon segment. Adenoma detection was not compared between the regimens.

Conclusion: OSS plus SF-ELS is a new, safe, and effective bowel preparation for colonoscopy.