GLP-1 Drugs Linked to Retained Gastric Contents Before Endoscopy

Clinical trial finds higher rates of residual stomach contents in patients who continued GLP-1 medication before procedure

Mar. 16, 2026 at 7:51pm

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A randomized trial found that patients on GLP-1 or GLP-1/GIP agonist medications who continued their usual dosing up until an endoscopic procedure had significantly higher rates of clinically significant residual gastric volume (RGV) compared to those who skipped their last dose before the procedure. Following a clear liquid diet the day before the endoscopy eliminated RGV issues regardless of GLP-1 drug hiatus.

Why it matters

Retained gastric contents can preclude successful endoscopic examination and increase the risk of regurgitation and pulmonary aspiration under anesthesia. This study provides evidence to guide recommendations on managing GLP-1 medications before endoscopic procedures.

The details

The single-masked OCULUS trial recruited 68 patients scheduled for upper endoscopy, endoscopic ultrasound, or ERCP. 25% of patients who continued their GLP-1 medication as usual had clinically significant RGV, compared to only 3.1% of those who skipped their last dose before the procedure. All cases of significant RGV precluded endoscopic examination, though there were no cases of aspiration or unplanned intubation. The rate of RGV was even higher, 46.7%, in the subgroup who underwent only upper endoscopy and continued their GLP-1 drug.

  • The OCULUS trial was conducted between July 2024 and May 2025.

The players

Tilak Shah

A physician at Cleveland Clinic Florida in Weston and the lead author of the study.

American Society of Anesthesiologists (ASA)

The professional organization that recently reversed its guidance on whether patients should stop taking GLP-1 medications before elective surgery.

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What they’re saying

“The risk of retained gastric contents in patients who follow standard fasting recommendations is high. Our results would suggest that patients who did not hold at least one dose of the medication prior to surgery or endoscopy should be rescheduled.”

— Tilak Shah, Physician, Cleveland Clinic Florida

“Point-of-care ultrasound could be investigated as an option to prevent rescheduling in these patients. Another option is to reschedule the procedure for the following day with clear liquids if the procedure is required urgently.”

— Tilak Shah, Physician, Cleveland Clinic Florida

What’s next

The researchers are conducting the OCULUS-2 trial to further investigate whether GLP-1 medications impact the likelihood of an inadequate bowel preparation before colonoscopy.

The takeaway

This study provides important evidence that patients on GLP-1 drugs should hold their medication or follow a clear liquid diet before endoscopic procedures to reduce the risk of retained gastric contents that could complicate the procedure or pose safety risks.