Hospitalized patients often struggle with bowel cleansing before a colonoscopy. However, a new multicenter randomized trial offers a more effective solution. Researchers compared three different volumes of polyethylene glycol (PEG) in hospitalized adults. Specifically, they looked at very low-volume (1-liter), low-volume (2-liter), and high-volume (4-liter) regimens. The results demonstrate that 1L PEG-ascorbate bowel preparation significantly improves high-quality cleansing rates compared to traditional methods.

In the study, researchers randomly assigned 665 patients to different split-dose regimens. Although all groups achieved similar rates of adequate cleansing, the 1-liter group excelled in high-quality results. Specifically, high-quality overall cleansing occurred in 46.9% of the 1-liter group. In contrast, the 2-liter and 4-liter groups reached only 35.3% and 37.4%, respectively. Furthermore, the 1-liter regimen proved more effective for the right colon.

Superior Results for 1L PEG-ascorbate bowel preparation

Patient preference also favored the lower volume. Despite more frequent vomiting and thirst, 84.2% of the 1-liter group expressed a willingness to repeat the prep. Consequently, clinicians should consider very low-volume PEG-ascorbate for hospitalized adults. This approach balances clinical efficacy with patient acceptance. Therefore, it may reduce the need for repeat procedures due to poor visualization. Importantly, the study excluded patients with active gastrointestinal bleeding or unstable conditions.

Frequently Asked Questions

Is 1L PEG-ascorbate as effective as high-volume 4L PEG?

Yes, the 1L PEG-ascorbate regimen achieved similar rates of adequate bowel cleansing as the 4L regimen. However, it significantly outperformed the high-volume option in achieving high-quality cleansing, especially in the right colon.

What are the common side effects of the 1L regimen in hospitalized patients?

The 1L PEG-ascorbate regimen was associated with more frequent vomiting and thirst compared to higher-volume options. Despite these side effects, patients reported a higher overall willingness to repeat the preparation due to its lower volume.

Why is high-quality right-colon cleansing important?

High-quality cleansing in the right colon is critical because this area is often the most difficult to clean. Better visualization improves the detection of flat adenomas and other lesions, leading to more accurate colonoscopy results.

Disclaimer: This content is for informational and educational purposes only. It does not constitute medical advice or establish a doctor-patient relationship. Professional medical guidance should always be sought for specific health concerns. Refer to the latest local and national guidelines for clinical practice.

References

Frazzoni L et al. Low-Volume Polyethylene Glycol for Bowel Preparation in Hospitalized Adults : A Multicenter Randomized Trial. Ann Intern Med. 2026 May 05. doi: 10.7326/ANNALS-25-05005. PMID: 42081822.

Machlab S et al. Real-world effectiveness and safety of 1L polyethylene glycol and ascorbic acid for bowel preparation in patients aged 80 years or older. Endosc Int Open. 2026; 14: a25259938. doi: 10.1055/a-2525-9938.

Park J et al. Updated bowel preparation regimens for colonoscopy: benefits and drawbacks. Clin Endosc. 2025 Dec 18. doi: 10.5946/ce.2025.001.