GLP-1 receptor agonist drugs like Trulicity and Ozempic have proved very effective in managing diabetes and obesity, but because of the way they work, they can present problems when it comes to preparing for a colonoscopy and endoscopy.
Though stool-based tests can also help to identify early-stage colorectal cancers, colonoscopy remains the gold standard both for its detection capabilities and because a gastroenterologist can remove suspicious polyps during the procedure, eliminating the need for a follow-up visit.
“One of the intended effects of GLP-1 agonist medications is to slow down the digestive tract,” explains University of Colorado Cancer Center member Swati Patel, associate professor of gastroenterology. “This results in the intended effect of helping individuals feel full with smaller meals, but patients often also experience another effect of a slow GI system — constipation. For people taking GLP-1 agonist medications who are getting ready for a colonoscopy, it’s important to let the GI team know about this. They will likely recommend holding the medication in advance of the procedure to minimize the anesthesia risk of aspiration of retained food material in the stomach. They may also advise a more aggressive bowel preparation to ensure the colon is adequately cleaned and flushed.”
An endoscopy is effective at detecting cancers and precancerous conditions in the upper digestive tract, primarily esophageal cancer and stomach (gastric) cancer.
For more information about the effects of GLP-1 drugs on colonoscopy and endoscopy prep, we sat down with Jennifer Christie, MD, director of the Division of Gastroenterology and Hepatology in the CU Department of Medicine.