Prospective blinded trial comparing 45-mL and 90-mL doses of oral sodium phosphate for bowel preparation before computed tomographic colonography

OBJECTIVE: To compare the efficacy of computed tomographic colonography (CTC) bowel preparation using single- (45 mL) versus double-dose sodium phosphate. MATERIALS AND METHODS: A hundred consecutive patients undergoing screening CTC were randomly assigned with either single (45 mL) or double dose of sodium phosphate. Stool/fluid tagging remained constant. Two radiologists with extensive CTC experience, blinded to the groups, prospectively scored the colon for residual stool and fluid by using a 4-point scale. RESULTS: There was an excellent cleansing in both groups characterized by low stool/fluid scores. A stool score of 1 or 2 (indicating a stool-free segment or only minimal particles <5 mm) was seen in 90.3% (271/300) of segments in the single-dose group and 87% (261/300) in the double-dose group. Similarly, there was minimal residual fluid with a score of 1 or 2 (indicating <25% of lumen occupied by fluid) in 82% (488/600) of segments in the single-dose group and 87% (522/600) in the double-dose group. Overall, no significant associations were noted between the sodium phosphate regimens and residual stool/fluid in most colonic segments. In addition, no significant differences were seen in the stool or fluid tagging. CONCLUSIONS: Both single- and double-dose sodium phosphate resulted in excellent colonic cleansing without any significant differences. Tagging of residual stool and fluid was equally excellent for both groups. These findings indicate that a single 45-mL dose of oral sodium phosphate, in conjunction with stool and fluid tagging, results in high-quality CTC bowel preparation that is comparable to the clinically proven double-dose regimen.