Serious adverse events associated with bowel preparation for colonoscopy in Japan: Systematic review

Bowel preparation for colonoscopy can lead to serious adverse events (AEs), raising significant safety concerns in colorectal cancer (CRC) screening. A systematic review of these serious AEs in Japan was performed to explore potential management strategies.

The Ovid-MEDLINE and Ichushi databases were searched from inception to March 2024. Domestic studies that reported serious AEs in adults aged 18 years and older who were administered bowel cleansing agents or laxatives for a scheduled colonoscopy, regardless of its purpose, were extracted. Serious AEs were defined as those requiring hospitalization or extended hospital stays. Selected studies were assessed for quality verification using the established checklist.

A total of 5049 articles were identified through database searches, and 54 articles were extracted based on selection criteria. Reports of the frequency of serious AEs were based on one case series study, which found 13.9 cases of bowel obstruction and 2.3 cases of bowel perforation per 100,000 colonoscopies. Multiple serious AEs caused by different agents were identified in 78 cases across 54 articles. These AEs were predominantly observed in elderly individuals and those with comorbidities. Though most cases were associated with diagnostic tests for symptomatic patients, some were also observed in primary screening or fecal test-positive individuals. The most common AE was induced by bowel obstruction, primarily in abdominally symptomatic patients, including one fatality.

The frequency and characteristics of serious AEs associated with bowel preparation for colonoscopy in Japan were presented. These findings may contribute to managing these AEs, specifically in CRC screening.