Small doses of the unabsorbable substance polyethylene glycol 3350 accelerate oro-caecal transit, but slow gastric emptying in healthy subjects

Polyethylene glycol 3350 increases stool frequency and accelerates colonic transit. Used as a laxative, it proved effective in patients with normal and slow transit. Although free of severe side effects, it may cause nausea and vomiting. The effect of this substance on upper gut transit has not been studied. To investigate the effect of polyethylene glycol 3350 on gastric emptying and oro-caecal transit in 12 healthy subjects. In a randomised controlled study, isosmotic polyethylene glycol 3350 electrolyte balanced solution, in the maximal recommended dose or isosmotic electrolyte solution, was administered after breakfast and lunch on separate days. Gastric half-emptying time and oro-caecal transit time were measured using [ 13C]-octanoate and lactose-[ 13C] ureide breath tests. Isosmotic polyethylene glycol 3350 electrolyte solution, as compared to isosmotic electrolyte solution, decreased oro-caecal transit time from 424 ± 28 to 314 ± 17 min ( P = 0.001). Gastric half-emptying time was significantly increased (84 ± 6 min versus 127 ± 14 min; P = 0.006). Polyethylene glycol 3350 accelerate oro-caecal transit in healthy subjects, but also cause an important delay in gastric emptying. The delay in gastric emptying may be of clinical significance in patients who have associated gastroparesis.