Oral sodium phosphate solution is a superior colonoscopy preparation to polyethylene glycol with bisacodyl

PURPOSE: The aim of this study was to compare the efficacy and patient tolerance of two bowel preparations for colonoscopy. METHODS: Three hundred twenty-three consecutive patients undergoing colonoscopy were randomly assigned to receive either oral sodium phosphate, or 2 liters of polyethylene glycol solution preceded by the stimulant laxative bisacodyl. Patients were asked to record the effects of the preparation, noting any vomiting, nausea, or abdominal pain, and to determine a discomfort rating on a scale of 1 to 5. One hundred sixty-nine patients were assigned to the oral sodium phosphate solution, and 154 to polyethylene glycol with bisacodyl. Surgeons were blinded to the preparation used and rated the quality of the bowel preparation on a scale of 1 to 5. RESULTS: Ninety-nine percent of patients in the sodium phosphate group drank all of the solution as opposed to 91 percent of patients in the polyethylene glycol with bisacodyl group. Patients in the sodium phosphate group reported significantly less discomfort (P = 0.002). No significant difference was reported for vomiting, nausea, or abdominal pain associated with the preparations. The quality of bowel cleansing was considered by the colonoscopists significantly better for the sodium phosphate group than the polyethylene glycol with bisacodyl group (P < 0.000001). CONCLUSIONS: Colonoscopy preparation with sodium phosphate solution is better tolerated and mote effective than polyethylene glycol with bisacodyl.