# Impact of Glucagon-like Peptide-1 Receptor Agonists (GLP-1 RAs) on Increased Residual Gastric Content in Patients With and Without Concurrent Colonoscopy: A Retrospective Case–Control Study

## TL;DR

This study shows that using GLP-1 RAs increases the risk of residual gastric content during endoscopic procedures, even with proper bowel prep.

## Contribution

The study is the first to specifically analyze the impact of GLP-1 RAs on residual gastric content during colonoscopy with adequate bowel preparation.

## Key findings

- GLP-1 RA users had significantly higher odds of increased residual gastric content.
- Among GLP-1 RA users undergoing colonoscopy, 86.4% had increased residual gastric content.
- No aspiration events were observed despite increased residual gastric content.

## Abstract

Background/Objectives: The use of GLP-1 RAs has dramatically increased with expanded indications for diabetes mellitus and obesity. Delayed gastric emptying due to these medications can lead to increased residual gastric content (RGC). While previous studies have focused on Esophagogastroduodenoscopy (EGD), few have specifically analyzed the impact of GLP-1 RAs on residual gastric content in patients undergoing concurrent colonoscopy with adequate bowel preparation. Methods: A retrospective, case–control study was conducted at Shanghai East Hospital from January 2023 to June 2025. Adult patients with increased RGC were identified as cases. Controls without increased RGC were randomly selected at a 1:2 ratio, matched for age and sex. Multivariable logistic regression was used to assess the independent association between GLP-1 RAs use and increased RGC. Results: Among 131,255 procedures screened, 3746 patients were included (1257 with increased RGC and 2489 controls). GLP-1 RAs users had higher odds of increased RGC in both unadjusted [OR 15.20 (95% CI 5.98–38.61)] and adjusted analyses [aOR = 13.31 (95% CI 5.07–34.93)]. Other significant risk factors for RGC included diabetes-related complications [aOR = 8.89 (3.15–25.12)]. Interestingly, among the enrolled patients who used GLP-1 RAs and underwent concurrent colonoscopy, 19 of the 22 patients (86.4%) exhibited increased RGC, whereas only 3 (13.6%) did not. Conclusions: Perioperative use of GLP-1 RAs is associated with an increased residual gastric content in patients undergoing EGD alone or with concurrent colonoscopy. There was no aspiration event related to residual gastric content. Our study highlights the need for vigilant preoperative assessment and individualized periprocedural management in patients on GLP-1 RAs undergoing endoscopic procedures, despite having standardized adequate bowel preparation.