A Retrospective Study of the Real-World Effectiveness of 8-L Polyethylene Glycol-Electrolyte Lavage Solution (PEG-ELS) Prep After Failure of Standard Prep

BACKGROUND/AIMS: While commonly prescribed in patients with inadequate bowel preparation, split-dose, 2-day bowel preparation (2DBP) with 8 L of polyethylene glycol-electrolyte lavage solution (PEG-ELS) has unknown effectiveness and safety. STUDY AIMS: To assess the effectiveness of a split-dose, 8 L-2DBP in patients with a prior failed bowel preparation. METHODS: We retrospectively identified all outpatients with inadequate bowel preparation on index colonoscopy with a 1-day split-dose prep who had repeat colonoscopy with a split-dose 2DBP (2015 to 2021) at a single Veterans Affairs medical center. We then assessed adequate bowel preparation (outcome), defined as excellent/good or Boston Bowel Prep Score (BBPS) 6 or greater, with a score of 2 in all colon segments. We also collected data on patient factors associated with inadequate preparation. Logistic regression was used to identify associations between these factors and inadequate preparation after split-dose 2DBP. All patient records were manually reviewed to identify potential adverse effects resulting in emergency room presentation. RESULTS: Among 400 patients given 2DBP, 83.5% (95% CI: 79.5%-87.0%) achieved an adequate preparation. In multivariable analysis, a higher CCI (OR: 1.14, 95% CI: 1.04-1.25), opioid use (OR: 1.97, 95% CI: 1.03-3.77), and rural home address (OR: 1.87, 95% CI: 1.01-3.46) were associated with inadequate bowel preparation. No attributable adverse events were recorded. CONCLUSION: In this difficult-to-prep population, split-dose 2DBP is effective in more than 80% of patients without evidence of severe adverse events. This intensive prep was less effective in patients with greater comorbidity burden, opioid use, or a rural home address.