Comparison of 4-L Polyethylene Glycol and 2-L Polyethylene Glycol Plus Ascorbic Acid in Patients with Inactive Ulcerative Colitis

Although colonoscopy preparation may cause symptom flares in patients with ulcerative colitis (UC), little is known about the standard preparation regimen in this population. We aimed to compare 4L polyethylene glycol (4L-PEG) with 2L polyethylene glycol plus ascorbic acid (2L-PEG-Asc) in quiescent UC patients. Patients with inactive UC undergoing colonoscopy for surveillance or checkup of mucosal healing were prospectively enrolled at 5 tertiary hospitals. They were randomly assigned to 4L-PEG and 2L-PEG-Asc groups. The Boston Bowel Preparation Scale (BBPS) was used for the preparation quality. Symptoms were assessed using the Simple Clinical Colitis Activity Index (SCCAI) before colonoscopy, at 1 and 4 weeks after the procedure. Overall, 109 patients were included in the study (4L-PEG group 53, 2L-PEG-Asc group 56, the mean age at diagnosis 42.25 years, male 77). The quality of preparation was comparable between the groups (BBPS ae<yen> 6, 96.2 vs. 92.9%, p = 0.679). Although 26 patients (23.8%) had increased SCCAI scores within 4 weeks after colonoscopy, resulting in a medication dose-up or add-on in 3 patients (2.7%), the rise in scores was not different between the groups. No serious adverse events during preparation were observed in either group. However, the 2L-PEG-Asc group was more likely to be willing to repeat the preparation with the same agent than the 4L-PEG group (82.1 vs. 64.2%, respectively, p = 0.034). PEG-based regimens with different volumes are equally effective and safe in inactive UC patients. 2L-PEG-Asc is more acceptable in this population as indicated by the willingness for further usage.