Low-Volume Polyethylene Glycol for Bowel Preparation in Hospitalized Adults

BACKGROUND: Adequate bowel preparation is essential for high-quality colonoscopy but remains challenging in hospitalized patients, and comparative data on preparation volume are limited. OBJECTIVE: To compare the efficacy, tolerability, and safety of very low-volume (1-liter [1L]), low-volume (2-liter [2L]), and high-volume (4-liter [4L]) polyethylene glycol (PEG) regimens for inpatient colonoscopy preparation. DESIGN: Multicenter, randomized controlled, endoscopist-blinded trial. (EudraCT: 2019-002799-15; ClinicalTrials.gov: NCT04708366). SETTING: Community and academic hospitals in Italy. PATIENTS: Hospitalized adults undergoing elective colonoscopy. INTERVENTION: Patients were randomly assigned (1:1:1) to split-dose 1L PEG-ascorbate, 2L PEG-ascorbate, or 4L PEG. MEASUREMENTS: Primary end point was adequate bowel cleansing (Boston Bowel Preparation Scale [BBPS] score ≥6 with all segments ≥2). Secondary end points included high-quality cleansing (BBPS score, 8 to 9), high-quality right-colon cleansing (BBPS score, 3), and willingness to repeat. RESULTS: = 219), adequate overall cleansing occurred in 82.0%, 78.0%, and 78.5% (absolute difference between the 1L and 2L groups [Δ1L-2L], 4.0 percentage points [95% CI, -3.4 to 11.4 percentage points]; absolute difference between the 1L and 4L groups [Δ1L-4L], 3.5 percentage points [CI, -3.9 to 10.9 percentage points]). High-quality overall cleansing occurred in 46.9%, 35.3%, and 37.4% (Δ1L-2L, 11.6 percentage points [CI, 2.5 to 20.5 percentage points]; Δ1L-4L, 9.5 percentage points [CI, 0.3 to 18.5 percentage points]). High-quality right-colon cleansing occurred in 40.6%, 29.5%, and 31.6% (Δ1L-2L, 11.2 percentage points [CI, 2.1 to 20.0 percentage points]; Δ1L-4L, 9.0 percentage points [CI, 0.0 to 17.9 percentage points]). Tolerability was good across regimens, with the highest willingness to repeat in the 1L group (84.2%), despite more frequent vomiting and thirst. LIMITATION: Patients requiring urgent colonoscopy for active gastrointestinal bleeding and those with severe/unstable comorbid conditions were excluded. CONCLUSION: In hospitalized adults undergoing elective colonoscopy, 1L PEG-ascorbate yielded higher rates of high-quality cleansing, including right colon, than 2L PEG-ascorbate and 4L PEG, with similar rates of adequate cleansing and high willingness to repeat. PRIMARY FUNDING SOURCE: Norgine Srl.