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Diabetic Preparation for an Endoscopy

Posted in: Education

If you, or a member of your family, has diabetes, please remember to follow the provided preparation protocol before an endoscopy. If you have questions, please call your primary care doctor.


  • Continue taking oral medications unless told otherwise by your primary care doctor or gastroenterologist.
  • Always continue basal insulins (Levemir, Lantus)
  • For fast-acting insulins (Novolog, Apidra, Humalog), you may have mealtime or correction doses
  • You should be able to continue correction scale if you have one — you are just correcting elevated blood glucose
  • Mealtime doses will depend on the amount of carbohydrates you’re taking in


Do not drink or eat anything that is either purple or red. Red and purple mimic blood and may affect the test results


When taking clear liquids, be mindful the carbohydrate-containing food you are drinking and eating (basic rule is 30 grams minimum, 45-60 grams maximum every 4-5 hours).

Examples of clear Liquids with 15 grams carbohydrates (for meal time):

  • 4 oz. of juice such as apple
  • 4 oz. of real soda (Sprite, 7-UP, Sierra Mist)
  • 8 oz. of Gatorade (not G2 type)
  • 1 popsicle
  • ½ cup sweetened gelatin


Between meals, you should drink non-carbohydrate-containing liquids.

Examples of non-carbohydrate-containing clear liquids (for between meals):

  • Diet soda
  • Water
  • Broth/Bouillon
  • Sugar free gelatin
  • Tea (without milk or sugar)