GLP-1 drugs like Ozempic increase the risk of food staying in your stomach during endoscopy procedures from 1% to 4.7%, but this risk is small and can be prevented. According to Gram Research analysis of a 2026 case-control study of 417 patients, following a 24-hour liquid diet before your procedure significantly reduces this risk, and serious complications were extremely rare in both GLP-1 users and non-users.
A new study from 2026 looked at how GLP-1 drugs (popular weight-loss and diabetes medications like Ozempic and Wegovy) affect stomach health during medical procedures. Researchers compared 417 patients taking GLP-1 drugs with similar patients who weren’t taking them. They found that GLP-1 drugs do increase the chance of food staying in your stomach longer, but the risk is small and can be reduced by following simple preparation steps like drinking only liquids for 24 hours before a procedure. The good news: serious complications were extremely rare in both groups.
Key Statistics
A 2026 case-control study of 417 patients found that GLP-1 drug users had a 4.7% rate of food retention in the stomach during endoscopy compared to 1% in non-users, but this risk was substantially reduced with 24-hour liquid diet preparation.
Among 212 GLP-1 drug users undergoing endoscopy in a 2026 study, only 1.9% required procedure cancellation, compared to 0.5% of 205 non-users, showing no significant difference in serious procedural complications.
In a 2026 analysis of 417 patients, zero cases of stomach food retention occurred in GLP-1 users who underwent both stomach and colon procedures combined, compared to 9.5% in those having stomach procedures alone, suggesting combined preparation may offer additional protection.
A 2026 case-control study found no difference in bowel preparation quality between GLP-1 drug users and non-users (16.5% inadequate preparation in both groups), indicating GLP-1 drugs affect the stomach but not colon cleanliness.
The Quick Take
- What they studied: Whether GLP-1 receptor agonist drugs (like Ozempic and Wegovy) cause stomach and bowel problems during endoscopy procedures, and whether simple preparation steps can prevent these issues.
- Who participated: 417 patients undergoing stomach or colon procedures: 212 taking GLP-1 drugs and 205 not taking them. All groups were matched by age, weight, and diabetes status to make fair comparisons.
- Key finding: GLP-1 drugs increased the risk of food staying in the stomach (4.7% versus 1%), but this risk was small and could be prevented with a 24-hour liquid diet before the procedure. No serious complications occurred in either group.
- What it means for you: If you take GLP-1 drugs and need an endoscopy, follow your doctor’s pre-procedure instructions carefully (especially the liquid diet), and you’ll likely have a safe procedure with minimal risk.
The Research Details
This was a case-control study, which means researchers looked backward at medical records from 2018 to 2023 to compare two groups of patients. One group (cases) was taking GLP-1 drugs and never stopped them before their procedure. The other group (controls) had diabetes but weren’t taking GLP-1 drugs. Both groups had the same types of procedures: either a camera down the throat (EGD) to look at the stomach, or a colonoscopy to look at the colon, or both.
The researchers carefully matched the two groups so they were as similar as possible in age, weight, and diabetes control. This helps ensure that any differences in outcomes were actually due to the GLP-1 drugs, not other factors. They tracked what happened during the procedures, including whether food remained in the stomach, whether the bowel was clean enough to see properly, and whether any procedures had to be stopped or repeated.
This study design is important because it separates the effects of GLP-1 drugs from the effects of diabetes itself. Previous research couldn’t tell which problem was causing issues—the drug or the disease. By comparing GLP-1 users to diabetics not using GLP-1, this study shows what the drug specifically does. The study also tested whether simple preparation steps (like a liquid diet) could reduce problems, which is practical information patients can actually use.
This study has several strengths: it included a large number of patients (417), used real-world data from an actual hospital system, and carefully matched comparison groups. However, it’s a retrospective study, meaning researchers looked at past records rather than following patients forward in time. The study was also from a single hospital system, so results might differ in other places. The study didn’t randomly assign people to groups, which is less powerful than a randomized trial, but it’s still reliable for answering this question.
What the Results Show
The main finding was that patients taking GLP-1 drugs had a higher rate of food remaining in their stomach during procedures (4.7% compared to 1% in the non-GLP-1 group). While this difference was statistically significant, the absolute numbers are small—meaning most patients in both groups had empty stomachs.
Interestingly, there was no difference between groups in bowel preparation quality (16.5% in both groups had inadequate preparation). This suggests that GLP-1 drugs affect the stomach but not the colon’s ability to be cleaned.
When researchers looked at whether procedures had to be stopped or repeated, they found no significant differences. Only 1.9% of GLP-1 patients had their stomach procedure stopped versus 0.5% of controls, and 7.6% of GLP-1 patients had colonoscopies stopped versus 6% of controls—neither difference was statistically significant. Most importantly, no patients in either group experienced serious complications like aspiration (food going into the lungs) or needed emergency anesthesia.
An interesting secondary finding emerged when researchers looked at patients who had both procedures (stomach and colon) versus stomach alone. Patients taking GLP-1 drugs who had both procedures together had zero cases of food in the stomach, while those having only the stomach procedure had a 9.5% rate. This suggests that the combination of procedures or the preparation for both might help clear the stomach better.
The study also confirmed that a 24-hour liquid diet combined with standard bowel preparation appeared to reduce the GLP-1-related stomach food retention risk substantially, though the exact mechanism isn’t clear.
Previous research had suggested that GLP-1 drugs increase stomach problems during procedures, but couldn’t separate this from diabetes itself. This study confirms that GLP-1 drugs do increase the specific risk of food retention, independent of diabetes. However, the absolute risk remains very low. The finding that preparation steps can reduce this risk is new and practical information that wasn’t well-established before. According to Gram Research analysis, this study provides the clearest evidence to date that proper preparation can mitigate GLP-1-related risks.
This study looked at past medical records rather than following patients forward, which means some information might be missing or recorded differently. The study was done at one large hospital system, so results might be different in smaller hospitals or different regions. The researchers didn’t randomly assign people to take or not take GLP-1 drugs—people chose their own medications—which could introduce bias. The study also couldn’t explain why combining procedures reduced stomach food retention, which limits our understanding of the mechanism. Finally, the study didn’t measure how long patients had been taking GLP-1 drugs, which might affect results.
The Bottom Line
If you take GLP-1 drugs and need an endoscopy procedure: (1) Tell your doctor you’re taking GLP-1 drugs—this is important information. (2) Follow the 24-hour liquid diet instructions carefully before your procedure. (3) Complete the standard bowel preparation as directed. (4) Don’t stop your GLP-1 medication before the procedure unless your doctor specifically tells you to. These steps appear to reduce any risks to very low levels. Confidence level: Moderate to High, based on this case-control study with good sample size.
This information is most relevant for people taking GLP-1 drugs (like semaglutide, tirzepatide, or liraglutide) who need endoscopy procedures. It’s also important for gastroenterologists and other doctors who perform these procedures. People with diabetes not taking GLP-1 drugs don’t need to change their preparation. People without diabetes taking GLP-1 drugs for weight loss should follow the same precautions.
The benefits of proper preparation are immediate—they reduce risk during the procedure itself, not over time. You should see the effects of following preparation instructions during your scheduled procedure.
Frequently Asked Questions
Do I need to stop taking my GLP-1 medication before an endoscopy?
No, research shows you should not stop your GLP-1 medication before an endoscopy. Instead, follow your doctor’s pre-procedure instructions carefully, especially the 24-hour liquid diet, which significantly reduces any stomach-related risks during the procedure.
What is the actual risk of complications if I take GLP-1 drugs and have an endoscopy?
The risk is very low. A 2026 study of 417 patients found that serious complications like aspiration or emergency anesthesia did not occur in either GLP-1 users or non-users. Food retention in the stomach occurred in only 4.7% of GLP-1 users and was preventable with proper preparation.
How can I reduce stomach problems during my endoscopy if I’m on GLP-1 medication?
Follow a 24-hour liquid-only diet before your procedure and complete all standard bowel preparation as directed by your doctor. Research shows this combination significantly reduces the risk of food remaining in your stomach during the procedure.
Does diabetes itself cause endoscopy problems, or is it the GLP-1 drug?
A 2026 study comparing GLP-1 users to diabetics not taking GLP-1 found that the drug itself increases stomach food retention risk, independent of diabetes. However, the absolute risk remains small and manageable with proper preparation.
Should my doctor know I’m taking GLP-1 before scheduling an endoscopy?
Yes, absolutely. Tell your doctor you’re taking GLP-1 drugs before any endoscopy procedure. This allows them to provide appropriate preparation instructions and monitor for any issues, though research shows serious complications are extremely rare.
Want to Apply This Research?
- If you take GLP-1 drugs and have upcoming procedures, track your medication adherence in the 30 days before your procedure, and log your completion of pre-procedure preparation steps (liquid diet days, bowel prep completion) to ensure you’re following all recommendations.
- Set reminders 48 hours before your scheduled procedure to begin your liquid-only diet. Log each day of diet compliance and bowel preparation steps in your app to ensure you complete all preparation requirements, which research shows reduces stomach-related complications.
- For users taking GLP-1 drugs: create a procedure preparation checklist in your app that includes medication timing, diet start date, bowel prep schedule, and appointment details. After your procedure, log any symptoms or complications to share with your healthcare provider and track your experience over time.
This article summarizes research findings and is not medical advice. GLP-1 receptor agonist medications should only be used as prescribed by your healthcare provider. If you take GLP-1 drugs and need an endoscopy procedure, discuss your medication with your doctor before the procedure—do not stop taking it without medical guidance. While this research shows that serious complications are rare, individual risks may vary. Always follow your doctor’s specific pre-procedure instructions, including dietary guidelines and bowel preparation protocols. This information is current as of the study publication date (June 2026) and may not reflect all emerging research.
This research translation is published by Gram Research, the science division of Gram, an AI-powered nutrition tracking app.