Preparing for a Colonoscopy When You Have CF

Due to the thick, sticky mucus associated with cystic fibrosis, adults with CF need to take additional steps for a successful colonoscopy. Learn more about why it's important to properly prepare for a colonoscopy and the steps you can take during your preparation.

8 min read
In this article
  • In people with cystic fibrosis, thick, sticky mucus can build up in the lungs, pancreas, and other organs — including the colon.
  • This, combined with people with CF often having a thicker and stickier stool, makes it more difficult to empty the contents of the colon when preparing for a colonoscopy.
  • Because of these unique challenges, adults with CF will need to undergo a more intensive bowel preparation than people without CF.

In people with cystic fibrosis, the defective cystic fibrosis transmembrane conductance regulator (CFTR) gene causes a thick, sticky buildup of mucus in the lungs, pancreas, and other organs — including the colon. This, combined with the fact that people with CF often have a thicker and stickier stool, makes it more difficult to empty the contents of the colon when preparing for a colonoscopy.

Because of these unique challenges, adults with CF will need to undergo a more intensive bowel preparation than people without CF.

The CF digestive system is very different than the average person's. Our systems are slower and full of mucus, so it takes much more time, and greater quantities of prep solution, to clean us out sufficiently. When I have a colonoscopy, I spend three or four days prepping for the exam.” — Amy Braid, an adult with CF, from the CF Community Blog

The Importance of a Proper Prep

Currently, colonoscopy is the only method that has been studied as an effective colorectal cancer screening test for people with CF. Colonoscopies allow the gastroenterologist or colonoscopist to both identify and remove as many polyps as possible before the polyps develop into cancer.

When the colon is not properly cleaned out, the gastroenterologist or colonoscopist may not be able to find polyps and may even require you to reschedule or repeat the exam.

Watch the animation above to see why it's important to properly prepare for a colonoscopy when you have CF and the steps you can take for a successful exam.

Preparing for a Colonoscopy With CF

Although the specific details of your bowel preparation regimen will depend on your individual health status and insurance coverage, there are common steps that people with CF should take to prepare for an effective exam:

  • Split up the bowel cleansing solution into three separate sets of 64 ounces. It's important to note that this is different from people without CF, who typically drink the solution at two separate times.
  • Drink several smaller washes rather than a single large wash to help breakdown mucus build-up.
  • Drink the last wash 4-6 hours before the exam.
Use this handout to guide your discussion with your endoscopist and CF care team to prepare for a successful colonoscopy.

If you have cystic fibrosis-related diabetes (CFRD), check with the doctor who manages your CFRD for specific diet and medication instructions. For example, you may need to schedule an early-morning appointment, adjust your insulin dose as part of your preparation, or discontinue certain medications in the few days leading up to your exam.

“The most important part of preparing for a colonoscopy when you have CF is splitting up the bowel cleansing solution into three or four separate sets of 64 ounces. It works great! By drinking the bowel cleansing solution in multiple, smaller washes, your colon gets cleaned out much better.” — Amy Braid, an adult with CF, from the CF Community Blog

Tips for Drinking the Bowel Cleansing Solution

  • Place the solution in the refrigerator and chill the glass prior to consuming as the solution often tastes better chilled.
  • Request an unflavored bowel cleansing solution.
  • Try squeezing in some lemon juice.
  • Drink the solution quickly and do not sip it in small amounts. A good pace is one 8-ounce glass every 10-15 minutes.
  • Drink through a straw to help keep some of the salty liquid from reaching your taste buds.
  • Rinse out your mouth with water, clear soda, or mouthwash after drinking.
  • Suck on hard candy or lollipops (but avoid red or purple).

Protecting Your Health

While preparing for your colonoscopy, you may experience issues such as weight loss, dehydration, and nausea.

Since people with CF have a more demanding bowel preparation regimen and are already at an increased risk for many of these problems, it is important to monitor your health and call your CF care team if you experience:

  • Lightheadedness
  • Fainting due to decreases in blood pressure or heart rate
  • Severe nausea that prevents you from completing the preparation

You may also lose weight while preparing for your colonoscopy since you can get dehydrated and will need to go on a special low-fiber diet as a part of the preparation process. If these or other issues last longer than 48–72 hours after the colonoscopy, contact your CF care team.

Prior to your colonoscopy, you will need to arrange for someone to drive you home once the colonoscopy is complete. Even though you will be awake when you leave, the medications administered during the procedure can impair your judgment and reflexes for the rest of the day.

Questions to Ask Your Colonoscopist

The physician who will perform your colonoscopy will differ depending on your center and will typically not be a member of your CF care team. For this reason, it is important to know what to ask your gastroenterologist or colonoscopist for a successful, high-quality exam. Questions to ask include:

  1. What is your polyp detection rate? (It should be 25 percent or greater overall, or 30 percent or greater for men and 20 percent or greater for women.)
  2. What is your cecal intubation rate? (It should be 95 percent or greater for screening colonoscopies and 90 percent or greater overall. The final standardized colonoscopy report should also indicate that the cecum was reached during the exam.)
  3. Did I prepare my bowel effectively? (A higher bowel preparation rating ensures an effective exam. This is usually discussed with the intake nurse before the colonoscopy and will also be documented in the standardized colonoscopy report.)
  4. Once the exam is complete, when can I expect to receive my results?

Although effectively cleaning out your bowels is one of the most important things you can do to prepare for a successful colonoscopy, there may be medical reasons why a colonoscopy cannot be completed as planned. For example, the physician performing the exam may stop the procedure may if he or she discovers something about your colon that increases your risk for injury — such as large lesions — or determines you need a different type of sedation.1

Access and Insurance Coverage

Although most insurance plans will cover colonoscopy screenings, you may still be charged for some services. Since screening for people with CF is recommended at a younger age than the general population, your insurance company may ask for additional information, such as a letter of medical necessity from your CF care team. For this reason, it is important to understand exactly what your insurance will cover and review your plan for specific details, including if the colonoscopist and any other care providers are in-network.

Cystic Fibrosis Foundation Compass case managers can help by explaining what your insurance plan covers to help you maximize your benefits and coordinate communication with your insurance company, gastroenterology practice, or any other providers on your behalf.

To learn more about colorectal cancer screening coverage, call CF Foundation Compass at 844-COMPASS (844-266-7277) Monday through Friday, 9 a.m. until 7 p.m. ET, or email

1. Am J Gastroenterol 2017; 112:1016-1030. Table 3.

Share this article
Adult Care | CF-Related Complications
Be Prepared for a Successful Colonoscopy When You Have CF: What the Guidelines Mean for You Download (PDF)

If you have CF, you are at higher risk for colon cancer. Get screened by age 40, avoid the home tests, and prep correctly for the colonoscopy.

Learn more
You Might Also Be Interested
Have questions? We’re here to help. Call us at 1-800-FIGHT CF

Mon - Thu, 9 am - 5 pm ET
Fri, 9 am - 3 pm ET


More Ways To Get Help