Safety of a novel 1L-polyethylene glycol-ascorbate solution for colonoscopy cleansing (REAL Study)

Background and aim: Very low-volume bowel preparation (BP) for colonoscopy with 1-liter polyethylene glycol plus ascorbate (1L-PEG-Asc) has displayed high tolerability and quality of bowel cleansing. Concerns have been raised regarding its safety. We aimed to evaluate the incidence of adverse events (AEs) following BP with 1L-PEG-Asc or 2L-PEG-Asc. Patients and methods: From January 2019 to September 2020, data from all consecutive adult outpatients who underwent colonoscopy in Our Unit were collected. AEs were assessed by reviewing the clinical and laboratory data of patients who attended the Emergency Department (ED) of Modena District Hospitals in the 7 days following the colonoscopy, and were classified as "BP-related" or "BP-unrelated". Results: During the study, 4069 (68.03%) and 1912 (31.97%) patients underwent colonoscopy after taking 2L-PEG-Asc or 1L-PEG-Asc, respectively. Regarding AEs, 77 (1.29%) patients attended ED, 53 (53/4069, 1.30%) and 24 (24/1912, 1.25%) after taking 2L-PEG-Asc and 1L-PEG-Asc. BP-related AEs were observed in 5 (5/4069, 0.12%) and 4 (4/1912, 0.21%) patients, respectively. The most frequent BP-related AEs were tachyarrhythmias (6/5981, 0.10%). Conclusion: The incidence rate of clinically relevant BP-related AEs is extremely low. This strongly suggests that 1L-PEG-Asc colonoscopy BP is as safe as 2L-PEG-Asc BP in a real-life clinical setting of unselected patients.