Ischemic Colitis Caused by Bowel Preparation for Colonoscopy.

BACKGROUND: Ischemic colitis is an adverse event which may occur during bowel preparation for colonoscopy. This study aims to clarify both the incidence and the risk factors of this complication. METHODS: This was a single-center, retrospective, observational study. All outpatients who were prescribed standardized preparation drugs for colonoscopy at the Kyoto Second Red Cross Hospital between November 2011 and March 2020 were included in the study. A split bowel preparation was carried out as follows; magnesium citrate with or without sodium picosulfate hydrate was/were used as a preparation drug on the day before the colonoscopy, and polyethylene glycol electrolyte solution or sodium phosphate was used on the morning of the endoscopic procedure. Patients were extracted from the electronic medical records and matched with the endoscopy database by examination date and hospital identification number. Following the endoscopic findings, both the incidence and risk factors for ischemic colitis arising after bowel preparation were examined. RESULTS: Among the 14,924 patients analyzed, ischemic colitis was observed in 14 patients (0.09%). Multivariate analysis revealed that old age (≥ 75 years old) and strong preparation (magnesium citrate with sodium picosulfate and polyethylene glycol electrolyte solution) for constipated patients were independent risk factors for ischemic colitis (odds ratio: 3.64 (95% confidence interval (CI): 1.36 - 9.77) and 4.27 (95% CI: 1.45 - 12.53), respectively). CONCLUSIONS: The age 75 years and above and strong preparation for patients with constipation were independent risk factors for ischemic colitis prior to colonoscopy. Careful attention should be paid to bowel preparation before colonoscopy for patients aged ≥ 75 years and for those with constipation.