[Low-dose polyethylene glycol 4000: digestive effects. Randomized double-blind study in healthy subjects]

It was recently demonstrated that low-dose polyethylene glycol 4000 (PEG) electrolyte lavage solution, a colonic lavage solution used for cleaning the gut before colonic procedures, is effective in the treatment of chronic constipation. The aim of our study was to determine the digestive effects of low-dose PEG 4000 without electrolyte addition in healthy subjects.

Sixteen healthy male subjects with normal transit were included in a randomized controlled cross-over study. Study design included 4 successive periods: pre-inclusion (12 days), treatment (7 days), wash out (7 days), treatment (7 days). Colorectal transit time measurement and stool collection for physical and chemical investigations were performed during each period. During treatment period, either 20 g/d of PEG without electrolyte addition or placebo was given to each subject.

With PEG, stool frequency increased significantly (1.26 +/- 0.09 with PEG versus 1.07 +/- 0.09 with placebo; P < 0.05) but no significant change in consistency was observed (P = 0.07). Total and segmental colonic transit time were comparable with PEG and placebo. Mean stool weight increased from 74 g/d, by increase of stool water output (54 g/d) and dry stool weight (20 g/d). Increase of stool water output was not associated with improvement in stool hydration: stool water content was comparable with PEG (75.4%) and with placebo (75.6%). No change was observed for the following parameters: stool electrolytes output, pH, organic acids, fecal output of fat, alpha-1-antitrypsin clearance, presence of red and white blood cells. Fecal output of protein increased significantly from 3.2 +/- 0.4 g/d to 6.0 +/- 0.7 g/d (P < 0.05).

No effect on colonic transit and on stool hydration was observed with low dose of PEG 4000. With 20 g/d of PEG 4000, electrolytes addition is not necessary.