Ozempic (semaglutide) is a medication from the GLP-1 receptor agonist family. Other drugs in this class include Wegovy and Mounjaro. These drugs copy the action of a natural gut hormone that helps regulate blood sugar and appetite. They have become widely used for type 2 diabetes and weight management.

How they affect the gut
  • Slow down stomach emptying: Ozempic delays how quickly food and fluid move from the stomach into the intestines. This helps reduce blood sugar spikes and keeps you feeling full for longer.
  • Reduced appetite: Many people notice fewer cravings, which can support weight loss.
  • Changes to gut bacteria: Research suggests Ozempic can shift the balance of gut bacteria, sometimes in ways linked to better metabolism.
Potential downsides
  • Digestive symptoms: Nausea, bloating, constipation, or diarrhoea are common, especially when starting treatment.
  • Too much slowing: In some people, food can remain in the stomach for longer than normal, leading to reflux, discomfort, or rarely a condition called gastroparesis.
  • Microbiome uncertainty: While bacterial shifts may be helpful, the long-term effects aren’t fully known and may contribute to bloating or unpredictable bowel habits.
Why this matters for colonoscopy

When we prepare for a colonoscopy, the goal is to have the stomach and bowel completely empty. Because Ozempic slows digestion, food and fluid can linger in the stomach or intestines. This increases the risk that your bowel prep won’t be as effective, making it harder for your doctor to see clearly. It can also raise the risk of aspiration (food or fluid entering the lungs during sedation).

For these reasons, we recommend commencing a clear fluid diet 24 hours before your colonoscopy. Your gastroenterologist will give you specific instructions so the procedure is as safe and accurate as possible.

Disclaimer – This article is for general information and educational purposes only. It is not a substitute for professional advice. Always consult a registered health professional regarding any health-related diagnosis or treatment options.