Background: Four liters of polyethylene glycol 3350 (PEG) with balanced electrolytes for colonoscopy preparation has had poor acceptance. Another approach is the use of electrolyte-free PEG combined with 1.9 L of Gatorade. Despite its widespread use, there are no data on metabolic safety and minimal data on efficacy. Our aim was to assess the efficacy and electrolyte safety of these two PEG-based preparations.
Methods: This was a prospective, randomized, single-blind, non-inferiority trial. Patients were randomized to 238 g PEG + 1.9 L Gatorade or 4 L of PEG-ELS containing 236 g PEG. Split dosing was not performed. On procedure day blood was drawn for basic chemistries. The primary outcome was preparation quality from procedure photos using the Boston Bowel Preparation Scale.
Results: We randomized 136 patients (66 PEG + Gatorade, 70 PEG-ELS). There were no differences in preparation scores between the two agents in the ITT analysis (7.2 ± 1.9 for PEG-ELS and 7.0 ± 2.1 for PEG + Gatorade; p = 0.45). BBPS scores were identical for those who completed the preparation and dietary instructions as directed (7.4 ± 1.7 for PEG-ELS, and 7.4 ± 1.8 for PEG + Gatorade; p = 0.98). There were no statistical differences in serum electrolytes between the two preparations. Patients who received PEG + Gatorade gave higher overall satisfaction scores for the preparation experience (p = 0.001), and had fewer adverse effects.
Conclusions: Use of 238 g PEG + 1.9 L Gatorade appears to be safe, better tolerated, and non-inferior to 4 L PEG-ELS. This preparation may be especially useful for patients who previously tolerated PEG-ELS poorly.