Diabetes: How to Prepare for a Colonoscopy - Topic Overview
Generally, if you take:
- Metformin, your doctor may have you stop taking it 48 hours before and after your colonoscopy.
- Oral diabetes pills or tablets, your doctor may have you stop taking your medicine on the morning of the test.
- Short-acting insulin, your doctor may have you stop taking it on the morning of the test.
- Long-acting insulin, your doctor may have you take only half of your usual dose on the morning of the test.
Bring your diabetes pills or insulin with you to take after the test as your doctor suggests. Don't take a double dose of medicines you've missed.
How to eat and drink
You'll get detailed instructions about food and drink when you get the medicines to cleanse your colon. Generally, the day before the test, you'll only be able to have clear liquids. These include water, tea, coffee, clear juices and broths, gelatin, and sports drinks.
Work with your diabetes doctor on how best to manage carbohydrate as you prepare for the test. You may want to plan 45 grams of carbohydrate for liquid "meals" and 15 to 30 grams for snacks. Apple or white grape juice and sweetened gelatins are a few options.