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Half PEG Prep for Colonoscopy

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Liquid Diet

Start a clear liquid (no solid foods) diet from the moment of waking up on the day before the procedure.

Clear Liquid Diet

  • Gatorade, fruit juice (no citrus), soda, popsicles without fruit or cream, gelatin without fruit, broth without fat, coffee, and tea
  • No solid food
  • No red, orange, or purple colored liquids
  • No dairy


Take the Medications

  • When you start the clear liquids, take one 5mg Bisacodyl (also known as Dulcolax) tablet at noon (12 pm).
  • Fill Prep Solution jug to fill line with water, shake to mix. Begin drinking 8 oz. glass of solution every 15 minutes between 4 and 6pm, until 2 liters is consumed (half of the jug). Discard remainder.
  • Drink the bottle of clear magnesium citrate 6 hours before your procedure.
  • You may have clear liquids up to 4 hours prior.

Do not eat or drink (not even water) anything 4 hours prior to your procedure.

  • Be sure to inform your doctors and nurses about any diabetic medications and/or blood thinners you take.
  • Take all medications for high blood pressure, heart conditions, or seizure disorder with water 4 hours prior to your procedure. This will be the last liquid you should have.
  • Bring rescue inhalers, asthma inhalers, diabetic medications, glucose monitor, and CPAP or BiPap machine with you to the procedure.
  • Please be sure to have a ride arranged and with you to take you home after the procedure. If you do not have a ride with you, your procedure will be cancelled. Your ride needs to be someone you know over 18 years of age, or a medical transport.

Please call 303.398.1355 option #4, if you have any questions or need to reschedule.


This information has been approved by Jeffrey King, MD (April 2022).