Is 1-Liter PEG Better for Inpatient Colonoscopy Prep?

Hospitalized adults often struggle with standard bowel preparation protocols for colonoscopy. Factors such as reduced mobility and multiple comorbidities contribute to poor cleansing quality in these patients. However, a recent study suggests that **1-Liter PEG Bowel Preparation** might be superior to traditional high-volume methods. Therefore, this multicenter randomized trial evaluated whether lower volumes of polyethylene glycol (PEG) provide adequate outcomes for inpatients.

Methodology of the Multicenter Trial

Researchers conducted the study across several academic and community hospitals to ensure broad applicability. They specifically compared split-dose 1-liter (1L) PEG-ascorbate with 2-liter (2L) and 4-liter (4L) regimens. Moreover, the primary goal was to measure the rate of adequate bowel cleansing among these hospitalized adults. Adequate cleansing was defined as a Boston Bowel Preparation Scale (BBPS) score of six or higher.

Superior Results for 1-Liter PEG Bowel Preparation

The results showed that the 1L group achieved adequate cleansing in 82.0% of cases. In comparison, the 2L and 4L groups reached 78.0% and 78.5%, respectively. Furthermore, the 1-Liter PEG Bowel Preparation group demonstrated significantly higher rates of high-quality cleansing. High-quality overall cleansing occurred in nearly 47% of patients receiving the ultra-low-volume dose. Consequently, this outperformed both the 2L and 4L groups by a notable margin. Similarly, cleansing in the right colon was significantly better with the 1L regimen.

Patient Tolerability and Clinical Takeaways

Patients generally tolerated the very low-volume preparation well despite some minor side effects. Although some participants reported thirst and vomiting, the willingness to repeat the procedure was highest in the 1L group. Because hospitalized patients often find high volumes difficult to finish, this finding is clinically significant. Ultimately, physicians should consider 1L PEG-ascorbate as a primary option for stable inpatients undergoing elective colonoscopy. This approach could improve diagnostic accuracy and patient comfort simultaneously.

Frequently Asked Questions

Q1: Was the 1-liter regimen as effective as the 4-liter regimen?

Yes, the 1-liter PEG-ascorbate regimen was found to be non-inferior to the 4-liter regimen for adequate cleansing and superior for high-quality cleansing.

Q2: What side effects were reported with the low-volume prep?

Patients in the 1-liter group reported more frequent thirst and vomiting compared to other groups, yet they still showed a higher willingness to repeat the preparation.

References

1. 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.
2. Xiao K et al. Low-Volume Bowel Prep Easier, as Effective as Standard Prep in Hospitalized Patients. ACG Annual Meeting. 2024.
3. Spadaccini M et al. Efficacy of 1 L polyethylene glycol plus ascorbate versus 4 L polyethylene glycol in split-dose for colonoscopy cleansing in out and inpatient. Dig Liver Dis. 2024.