A systematic review including 8 RCTs with a total of 1,315 subjects was abstracted in DARE. Failure to complete preparation was less common with NaP than with PEG (OR 0.23, 95% CI 0.18 to 0.28, NNT = 7). Adequate preparation was more common with NaP (RR = 1.19, 95% CI 1.09 to 1.32, NNT = 9). Excellent preparation was more common with NaP (Rr = 1.28, 95% CI 1.11 to 1.48, NNT = 10). There were no consistent, clinically important differences in symptom side effects. Sodium phosphate was slighly less expensive than PEG.