Sodium phosphate is superior to polyethylene glycol in bowel cleansing and shortens the time it takes to visualize colon mucosa

BACKGROUND: Both sodium phosphate (NaP) and polyethylene glycol-electrolyte (PEG-EL) have been used to cleanse the bowel prior to colonoscopy, and recent reviews suggest that the former is the more effective and convenient cleansing regimen. The aim of this study was to compare the bowel cleansing effect of NaP solution with that of PEG-EL solution and to evaluate whether the cleansing effect correlates with the time needed to perform colonoscopy. METHODS: 111 patients admitted for colonoscopy were randomized to receive either 90 mL oral NaP or 4 litres of PEG-EL solution. Cleansing was scored blindly by one colonoscopist and the following times were recorded: caecal intubation, withdrawal and total colonoscopy. RESULTS: Of all the patients included in the study, 99 were evaluable. The mean and standard error of the mean (+/-S(chi)-) cleansing score was 3.64 +/- 0.16 in the NaP group and 2.69 +/- 0.9 in the PEG-EL group (P = 0.005). The mean (+/-S(chi)-) caecal intubation times were 6.39 +/- 0.50 min and 5.39 +/- 0.41 min (P = 0.13), the withdrawal times 4.26 +/- 0.20 min and 5.78 +/- 0.34 min (P = 0.0001) and the total colonoscopy times 10.65 +/- 0.52 min and 11.17 +/- 0.56 min (P = 0.50) in the NaP and PEG-EL groups, respectively. The subgroup of patients with a cleansing score of 3 or more was associated with shortened colonoscopy withdrawal time compared to the group scoring below 3. CONCLUSIONS: Better cleansing of the large bowel shortens colonoscopy withdrawal time. Sodium phosphate is a more effective bowel-cleansing regimen than polyethylene glycol, and the better cleansing result is associated with shortened colonoscopy withdrawal time.