The prepping process can seem very daunting and is one of the main reasons patients avoid having a colonoscopy. When patients see that it could be a few days of changing your diet, adjusting medications, being off work, needing a ride to and from the procedure- It may cause patients to have even more questions. We have compiled the most frequently asked questions in hopes we can educate our patients for the best possible outcome with their prep.

Frequently Asked Prep Questions

Why can’t I take my vitamins and supplements that my doctor prescribed?

There are so many vitamins and supplements that patients take, some prescribed, some that they read about and some that friends recommend.  It is not possible for your gastroenterologist to know every one of them and their list of ingredients.  Some supplements contain weight loss components that can cause a heart arrythmia when under anesthesia or thin the blood (such as fish oil). Therefore, the safest course of action is to stop vitamins and supplements 1 week before your procedure.  If you insist and taking a vitamin or supplement, please call our office and ask to speak to a nurse regarding your issue.  Additionally, please stop all fiber supplements and iron 5 days before your colonoscopy.


Do I have to drink the whole colon preparation if I have clear bowel movements the night before my procedure?

 The short answer is yes.  You have 20-25 feet of small intestine and food that you ate 2 days ago is still moving through your GI tract.  The reason for the split dose of prep is to clean out your colon in 2 stages to make sure any waste products that are moving through the night and entering your colon are removed in the morning.

However, if you are taking a large volume prep (Trilyte, Colyte, Gavilyte, PEG prep) you are only required to take ½ of the remaining 2 liters in your jug of prep in the morning provided what is coming out is yellow or clear water.  It is ok to have some floating material or a small amount of sediment in the bottom of the toilet.  Ideally, it should look like you are urinating out of your bottom.  The better the colon prep, the better the exam and our ability to see the lining of your intestine.


Do I have to take the colon preparation at the exact time on my instructions because I work and I will not be home by that time?

Your doctor understands that you work and the times of the prep may be adjusted up or down on the night before your procedure.  Recognize that if you start your prep later than 6pm, your response will occur later and you may get less sleep.

In the case of the prep Clenpiq/SuTab/Suprep your response may not start for 3-4 hours so if you start your preparation at 8pm you may not start eliminating until midnight. If your procedure is at 8am, you will need to get up at 3am to take the second bottle of preparation.

In the case of Trilyte, Colyte, Gavilyte, or PEG prep you may adjust your start time on the evening before your procedure.  Further, when you take this large volume prep it is ok to space out the glasses of prep if you are full.  The instructions say to drink a glass every 10 minutes until 2 liters is gone.  If the rate of drinking the prep is too fast, slow down taking 2-3 glasses of prep then wait ½ an hour and resume drinking.  The stomach normally empties every 30 to 45 minutes when it is just fluids.


Can I mix Gatorade or Crystal Light with my Trilyte, Colyte, Gavilyte, or PEG prep? 

Yes, however Crystal Light yellow lemonade is the preferred flavoring for the prep.  Gatorade could be added but this will add additional volume and salt as Gatorade is a little salty and so is the preparation which could be off putting when you are drinking a large volume. Koolaid orange, lemonade, apple, mango, can be added.  The recipe for Koolaid and Crystal Light is 2-3 TBSP per 4 Liter prep.  Suggest that you pour 1 glass of prep solution and mix in ½ to 1 tsp of Crystal Light or Koolaid to see how it tastes before you add flavor to whole 4 Liters incase you find the flavor off putting.


Can I have breakfast before my procedure if it is in the afternoon?

No!  On the day of your procedure if you are having an EGD you may have WATER ONLY up until 6 hours before your procedure.

No! On the day of your procedure, if you are having and EGD/Colonoscopy or a colonoscopy you should finish your colon preparation 4 hours before your scheduled procedure. After you finish the colon prep, no food, fluid, gum, or candy is allowed.  Sometimes it is hard to finish the second part of the preparation in one hour.  NOTHING should pass your lips except the prep on the morning of your procedure and you must be finished 2 ½ hours before the procedure (this includes taking medication) or your procedure may be cancelled or delayed.


Will I talk with my doctor before my procedure?

Absolutely!  You will have the opportunity to speak to your anesthesia provider and your gastroenterologist before you are given any sedation.  If you have questions or concerns, they will be addressed before your procedure?