Colonoscopy Prep

Prep. It’s one of the most dreaded steps of a colonoscopy. It’s also one of the most important.

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It’s crucial that your gastroenterologist gets a good look inside of your colon to properly screen for colorectal cancer. If you don’t have a thorough colonoscopy prep, your colon may not be clear of stool, which means your doctor can’t see the walls of the colon clearly. If this happens, you may need to repeat the procedure, both the prep and the colonoscopy. Don’t let this happen to you!

Which Colonoscopy Prep Should I Use?

There are several prep brands to choose from, and it can get confusing to know which one to use. Your doctor will recommend what they prefer. 

The volume of prep that you’ll need to drink depends on the brand, and it ranges from 10 ounces to 128 ounces. It’s worth noting that lower-volume preps need to be supplemented with a similar volume of water as the larger-volume preps. Basically, you’ll be drinking a lot if you use a liquid prep! 

There are pill formula options as well, which also require large volumes of water to work effectively. 

The cost of each prep differs. Talk to your doctor and your insurance company to figure out which option works best for you and your budget.

Tips to Improve Your Colonoscopy Prep

  1. Clear your schedule. You’re going to want to be home or somewhere comfortable with access to a toilet from when you start your prep until you leave for your colonoscopy appointment. Cancel any other plans you may have had on your calendar.
  2. Prep for your prep. Refrigerate your medication before you drink it, and try drinking it from a straw. Many people think this improves the taste. 
  3. Hydrate yourself. Drink clear liquids often—water, coconut water, electrolyte drinks. 
  4. Follow the plan. Your prep will come with instructions from your doctor. Follow the directions exactly so you can ensure a clean colon for your exam.
  5. Stay close to the bathroom. Trust us on this one! Keep a good book, movie, and magazine on hand. Splurge on plush, soft toilet paper to help avoid irritation. Flushable wipes help too.

Visit the blog to read Colonoscopy prep: 8 expert tips for the night before for more information and download Fight CRC’s Screening Mini Magazine.

Colonoscopy Prep Timeline


  • Ask your health care provider any questions about the procedure. Make sure they know your current medications.
    • Tell them if you take blood thinners or diabetes medications. You may need to adjust your medication prior to the colonoscopy.
  • Line up a ride. You’re required to have someone drive you home after your colonoscopy.
  • Kick some foods to the curb. About a week before your exam, begin a low-fiber diet (don’t eat raw fruits or veggies, whole corn kernels, nuts, or seeds). This will help you empty your bowel during your prep.
  • If needed, request time off from work and/or line up childcare.


  • The morning before your colonoscopy, prepare your medication (prep) exactly as instructed. Once prepared, you can put any liquid in the refrigerator and let it get cold.
  • Don’t eat! This day requires you to be on a liquid diet, free from any red, purple, or orange beverages.
  • Get everything together for tomorrow. Pack a list of the medications you take, any important medical information, your glasses, cell phone and charger, and anything else you may need.
  • In the evening, at the time specified by your doctor, begin your prep. Shortly after this, you’ll find yourself in the bathroom a lot as your colon gets cleaned out.
  • For more information on prepping the night before, view our 8 expert tips for the night before your colonoscopy.


  • If you took a split-dose prep, take the remaining half six hours prior to your appointment. Your doctor will tell you what time to take this. Don’t drink anything at least two hours prior to the procedure. (Double-check with your doctor about the time you should discontinue drinking.)
  • When you arrive at the office, you will check-in, make payment (if applicable), and go through an intake that includes heart monitoring and blood pressure measurements.
  • After the exam, you will be monitored. It’s normal to have cramps or feel slight discomfort after the procedure.
  • You can eat again! Start slowly, with easy-to-digest foods since you haven’t eaten for a day. Your doctor will tell you if there are any food items to restrict.


  • Avoid alcohol for 24 hours after your procedure. 
  • Take it easy.
  • Go back to your normal schedule 24 hours after the procedure. 
  • If you have any concerns, follow up with your doctor.