Another Benefit of Split-Dose Bowel Preparation?

Patients sometimes complain of altered bowel habit after bowel preparation for colonoscopy. To assess whether the dosing method affects the intestinal microbiota, investigators randomized 23 healthy participants to receive 2 L of polyethylene glycol–electrolyte lavage solution with ascorbic acid in a single dose on the morning of the study or as split doses (1 L each) on the evening before and morning of the study. The intestinal microbiota was analyzed using fecal samples taken at baseline, after bowel cleansing, and at 14 and 28 days.

Both dosing regimens decreased the microbial load dramatically, and some patients had significant alterations in the types of bacteria present. Although both groups showed full recovery of bacterial populatio…