Food left in the stomach or stool left in the bowel can impede a doctor's ability to successfully perform an endoscopy or colonoscopy.

Now, research finds this scenario is more likely if the patient is taking popular new weight-loss meds such as Ozempic, Wegovy, Mounjaro or Zepbound.

For these patients, "inadequate bowel preparation was more common" before endoscopy or colonoscopy, according to researchers led by Dr. Ruchi Mathur. She's an endocrinologist and gastrointestinal researcher at Cedars-Sinai in Los Angeles.

Mathur's team published its findings Oct. 1 in the journal JAMA Network Open.

As the researchers noted, prior studies have suggested that people taking GLP-1'medications might face a higher odds of "aspirating" food when undergoing procedures requiring anesthesia.

Because the drugs can also cause constipation and a delayed emptying of the stomach, Mathur's group wondered if the meds might leave residues in the digestive tract that could interfere with the clarity of endoscopic procedures.

To find out, they looked at endoscopies and colonoscopies performed on 209 patients who were all overweight or obese (mean BMI of about 34) and averaging about 63 years of age.

Seventy of the participants were taking a GLP-1 medicine, with almost half of that group taking Ozempic or Wegovy. The other 139 participants were not taking a GLP-1 med.

For 23 folks undergoing an esophagogastroduodenoscopy (EGD), where a camera is snaked through the throat into the stomach, food was still present in the stomach of people taking a GLP-1 in four cases.

In contrast, that never occurred among those who didn't take a GLP-1.

Among 140 patients who underwent colonoscopy or a colonoscopy-plus-EGD, "inadequate bowel preparation" (stool retained in the bowel) was observed in 21.3% of those who were taking a GLP-1 medicine versus 6.5% of those who were not, Mathur's team reported.

The good news: "No aspiration events, respiratory distress or aspiration pneumonia" occurred among the patients, regardless of whether they'd taken one of the weight-loss treatments or not, the researchers said.

Still, the rise in risk for stomach and/or bowels containing food or stool is troubling, the researchers said, since it brings "significant risks for missed lesions, patient dissatisfaction and procedure cancellation, with wasted resources."

According to the researchers, the findings suggest the need for more research to determine if updated guidelines regarding GLP-1 use before endoscopies are needed.