A randomized clinical study comparing reduced-volume oral sulfate solution with standard 4-liter sulfate-free electrolyte lavage solution as preparation for colonoscopy.

Low-volume bowel preparations for colonoscopy improve tolerability. We compared the efficacy, tolerability, and safety of a new low-volume sulfate solution with a standard 4-L polyethylene glycol electrolyte lavage solution as bowel preparation for colonoscopy. Multicenter, single-blind, randomized, noninferiority study. Five academic and community endoscopy centers in the United States. One hundred thirty-six outpatients undergoing colonoscopy. Patients were randomized to receive 4 L sulfate-free electrolyte lavage solution (SF-ELS) given the night before colonoscopy versus 12 oz oral sulfate solution (OSS) given in equally divided doses the evening before and the morning of colonoscopy. Successful (ie, good or excellent) bowel preparation. Successful bowel preparation was more frequent with OSS than with SF-ELS (98.4% vs 89.6%; P = .04). Excellent preparation also was achieved more frequently with OSS (71.4% vs 34.3%; P < .001). Patients receiving OSS had less residual stool in the cecum and ascending colon and less residual fluid in the cecum and ascending, transverse, and descending colon compared with SF-ELS. The percentage of patients with GI side effects and adverse events was not significantly different between the 2 groups. The OSS was administered in split doses, whereas the SF-ELS was administered the evening before (which is its FDA-approved regimen). Oral sulfate solution is promising as a safe low-volume preparation for colonoscopy. ( NCT00856843.).