Comparison of standard polyethylene glycol and two doses of oral sodium phosphate solution in precolonoscopy bowel preparation: a randomized controlled trial.

Background and study aims : This study was undertaken to compare the efficacy, side effects and patient acceptance of standard 4liters polyethylene glycol (PEG) and 2 doses of sodium phosphate (NaP) solution for precolonoscopy colon cleansing. Patients and methods : A total of 182 patients were randomized to receive either standard 4-L PEG (88 patients) or 80 mL of NaP (94 patients) in a split regimen of two 40 mL doses separated by 24 h, prior to colonoscopic evaluation. The primary endpoint was the segmental assessment of colonic wall visualization. Secondary outcomes included percent of assumed preparation, and the patient tolerance and acceptability. Results : A significantly higher completion rate was found in the NaP group compared to the PEG group (84.3% vs 62.9% ; difference, 21.40% ; 95% confidence interval [CI], 8.29% to 34.51% ; p = 0.001). PEG solution caused more nausea than NaP solution ( p= 0.024). Patient acceptance for bowel preparation with NaP was greater (p = 0.019). Adequate colon wall visualization was achieved in similar proportion of patients in both groups with exception of the descending colon, where NaP regimen was superior (72.0% vs 52.9% ; difference, 19.10% ; 95% CI, 5.20% to 33.00% ; p = 0.012). Conclusions : Two doses of NaP solution, taken 24 h and 12 h before colonoscopy, tend to guarantee superior results in colonic cleansing with respect to standard 4-liters PEG solution. Taking the second dose of NaP 24 h after the first dose reduces side effects and allows achieving a more satisfactory compliance of the patient. (Acta gastroenterol. belg., 2008, 71, 1-6).