Objectives: The aim of the study was to assess in normal subjects the changes in stool consistency and dilution water during the ingestion of small doses of polyethylene glycol (PEG) 5.9 g/d. Dilution water is the water located outside solid structures (bacteria and food residue).
Methods: Each stool passed by 16 non-constipated male volunteers was collected during 3 weeks. PEG was ingested from days 1 to 7, and stools collected during the ingestion of PEG were compared with those collected at least 24 h after the last fecal excretion of PEG (control fecal data). Consistency, fresh and dry weight, dilution water, nitrogen, electrolytes and PEG were quantified in each stool.
Results: Stools were softer during the ingestion of PEG (P < 0.01) and dilution water increased significantly (49.4 +/- 1.7 vs 37.6 +/- 2.6 mL/100 g feces, mean +/- SD, P < 0.02). PEG induced variable effects among individuals according to the consistency and dilution water measured during the control period.
Conclusion: Low doses of PEG (5.9 g/d) soften stools particularly when feces are harder. This effect is due to changes in dilution water (water outside fecal solid structures).