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 com- pare the efficacy, side effects and patient acceptance of standard 4- liters 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 out- comes 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% ; differ- ence, 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 supe- rior (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, 15-20).