Colonoscopy Prep 101: What to Expect When It’s Time to Prep

Colonoscopy prep

While the U.S. sees right around 19 million colonoscopies every year, getting through colonoscopy prep is still no easy feat. From foul-tasting prep powders to the uncomfortable reality of clearing your bowels, it’s safe to say colonoscopy prep isn’t exactly an experience to look forward to or write home about. But with a clear understanding of what to expect—and some expert tips on how to best prepare—the dreaded prep process can become a bit more comfortable. 

Today, we’re offering up all you need to know about what to expect during colonoscopy prep. Read on for the information, empowerment, and encouragement you need to get that all-important procedure performed.

How important is getting through colonoscopy prep?

While there are times we can get away with secretly skirting our doctor’s orders—colonoscopy prep isn’t one of them. If you neglect to get through prep properly (the end-goal of which is completely emptying your bowels so your doctor can clearly see inside the colon), your physician will absolutely know and—more importantly—won’t be able to perform the procedure.

When you take into the account the fact colorectal cancer is the second leading cause of cancer death—and that a staggering 60 percent of colorectal cancer deaths could have been prevented with screening—it’s clear to see why getting through prep is imperative. It’s the first—and most necessary step—for getting vital, possibly life-saving information about your colorectal health.

What should I expect during colonoscopy prep?

One week before your colonoscopy…

You’ll want to begin cutting down on heavy, high-fiber foods and opting for smaller, more digestible meals in the days leading up to your procedure. While it’s tempting to get in as many filling foods as you can before hitting the fasting period, high-fiber foods only make the dreaded colonoscopy prep process that much more uncomfortable. Plus, fibrous foods can leave behind residue in your colon that can make it difficult for your doctor to see polyps (the entire point of a colonoscopy). Foods to avoid include:

  • Nuts
  • Seeds
  • Legumes
  • Raw fruits and vegetables
  • Brown rice, oatmeal, wheat bread, and whole grains

2 days before your colonoscopy…

Aside from continuing to avoid high-fiber foods, the most important thing you can do at this point in the process is to hydrate (and then hydrate some more…and some more). The 24-hour colonoscopy prep period before your procedure can be grueling on your body—and can lead to serious dehydration. In addition to drinking plenty of water, PreOp drinks and natural electrolyte drinks will give your body the clean, clinical-grade hydration, vitamins, and minerals it needs to head into the 24-hour prep period strong, nourished, and hydrated (without the colored dyes, harmful synthetics, and added sugars you’ll find in sports drinks and non-medical-grade hydration beverages).

24 hours prior to your procedure…

This is where the real work begins, as you’re officially in the fasting window and on a clear liquid diet. Here’s what you can expect…

  • The Goal: The entire point of this period is to completely clear your bowels so your doctor can see inside the colon.
  • The Bowel Prep Liquid or Powder: In addition to clear liquids (think: anything you can see through—water, electrolyte drinks, apple juice, presurgery drinks, apple juice, etc.), you’ll need an oral solution (in the form of a liquid or a powder that you mix with another liquid) designed to help you empty your bowels. Your doctor may have you take the entire oral solution the night before your colonoscopy—or she may have you split the solution into two portions and drink one the night prior and finish the second portion the morning-of.
  • What Happens: As you begin taking your prep powder or liquid, you’ll experience the frequent urge to empty your bowels. This will happen until your movements become more liquid-like and eventually turn clear or yellow (a sign your colon is clear). The bowel prep may also cause you to experience:
  • Nausea
  • Bloating
  • Thirst
  • Dizziness

Is there any way to make colonoscopy prep easier?

Brilliant question! And the answer is YES. Like you, our team of nutritionists and beverage scientists knew there had to be a better way, so we developed CF(Rehydrate)®—a medical-grade, clear-and-colorless, great-tasting natural electrolyte drink—and bundled it with the #1 recommended gentle laxative to create our fan-favorite CF (Colonoscopy Kit)®.

The end-result is enhanced hydration, boosted electrolytes, reduced discomfort, and a faster, easier post-op recovery. In addition to getting medical-grade hydration from CF(Rehydrate)®, the electrolyte drink that comes in their colonoscopy preparation kit, patients also love to use it as a “chaser” and mask the taste of their prep powder. PRO TIP: CF(Rehydrate)® is delicious when chilled, so be sure to place your bottles in the fridge a few days before your colonoscopy prep.

What if my doctor already prescribed me a bowel prep liquid?

If you already have a prep liquid or powder, you don’t need our entire colonoscopy preparation kit. Instead, you can just opt for CF(Rehydrate) (our electrolyte drink with added immune-boosting ingredients) to use as part of your clear liquid diet (and, again, to mask that terrible-tasting prep liquid).

Here’s what people are saying about the difference CF (Colonoscopy Kit)® made in their colonoscopy prep process…

“At 70+ years old with significant diverticulitis, I have had many dreaded colonoscopy preps. My last experience was totally different thanks to just 3 bottles of ClearFast” – B. T.

“I felt great and will always repeat this routine in the future! For my last colonoscopy, I was stuck 7 times for my IV as I was so dehydrated. This last experience was a ‘1 stick miracle’! I have highly recommended ClearFast to any eligible patient.” – A. S.

“Having to go through my first colonoscopy, my worst fear was not only having to drink the solution, but doing so on an empty stomach with the possibility of being nauseous! Sipping on ClearFast after each glass made it bearable, as it tastes good! And, it was comforting to know that it was full of nutrients.” – P

“I used ClearFast during last year’s colonoscopy prep, and after the procedure, I bounced right back and felt normal in record time. Good stuff!” – Amazon customer

“Used ClearFast the day prior to colonoscopy prep. Did not experience the jitters from fasting. Great taste also.” – Amazon customer 

“Will buy again. Now I actually don’t dread my next colonoscopy”


Overall, while colonoscopy prep is absolutely necessary—feeling miserable isn’t. With a clear idea of what to expect—and the power of a colonoscopy prep drink that offers proven, clean, clinical hydration on your side—you can get through the prep period (and get those all-important results) as painlessly as possible.


Ready for more goodness? Browse the rest of the CF Nutrition blog for empowering health, wellness, and lifestyle tips. And don’t forget to give your body the best chance at recovery with the clean, clinical replenishment of CF(Rehyrdate)® and the natural complex carbs you’ll find in CF(Preop)®.


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