Low-Volume Bowel Prep Matches High-Volume Methods in Landmark Study

A major clinical trial has found that a low-volume bowel preparation method works just as well as traditional high-volume solutions for hospitalised patients. The INTERPRET study compared three different polyethylene glycol (PEG) regimens and discovered that a 1-litre PEG-ascorbate mix provided the best results. This breakthrough could change how hospitals prepare patients for colonoscopies in the future. The trial involved multiple medical centres and tested three PEG volumes: 1 litre, 2 litres, and 4 litres. Researchers found that the smallest volume—1 litre with added ascorbate—delivered superior bowel cleansing compared to the larger amounts. Importantly, patients using the low-volume solution reported fewer issues and were more willing to undergo the procedure again.

The study also showed no increase in adverse effects with the 1-litre regimen, challenging the long-held belief that larger volumes are safer. Instead, the ascorbate-enhanced solution improved mucosal visibility, particularly in the right colon, which could lead to better diagnostic accuracy. Experts involved in the trial stressed that these findings should be carefully applied, as further research is needed for outpatient settings.

Hospitals may soon rethink their current protocols based on these results. The shift towards a patient-friendly, low-volume preparation aligns with a broader trend in gastroenterology—prioritising both clinical effectiveness and patient comfort. The INTERPRET trial’s conclusions suggest that a 1-litre PEG-ascorbate regimen could become the new standard for inpatient bowel preparation. Guideline committees and hospital formularies are expected to review their recommendations in response. If adopted widely, this approach may simplify clinical workflows and improve patient experiences during colonoscopy procedures.