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Ensure success with colonoscopy prep

Focused on Health - March 2014

by Adelina Espat and Brittany Cordeiro

If you really want to know what’s going on inside your colon, don’t show-up for a colonoscopy without a clean colon.colonoscopy

That’s because a clean colon happens to be the most important part of a successful exam.

“If the prep isn’t done right, and your colon isn’t completely clean, the danger is that we won’t see important, potentially cancer-causing, polyps,” says Robert Bresalier, M.D., professor in the Department of Gastroenterology, Hepatology and Nutrition at MD Anderson.

Polyps are small growths on the lining of the colon that can become cancer. Polyps shaped like a mushroom are easy to detect during a colonoscopy. Polyps that are flat are harder to detect, especially if your colon isn’t clean. “And, evidence suggests that some flat polyps tend to grow into cancer faster than other polyp types,” Bresalier says.

Another great benefit to having a clean colon is that your doctor can spend more time carefully examining your colon instead of trying to wash away any waste that’s left. And, that means you won’t have to come in for a repeat exam.

“During a colonoscopy, we’re not looking for just cancer but also subtle lesions that can turn into cancer,” Bresalier says. “So, we don’t want to miss anything.”

READ ALSO: Colon screening: Colonoscopy vs. virtual colonoscopy

Steps to a successful prep

Your goal should be to get your colon as clean as the palm of your hand before you go in for your colonoscopy. Here’s how to reach that goal.drink water

24 hours before your exam:

  • Drink clear liquids only. It’s okay to have clear broth and non-colored Jell-O.
  • Don't eat solid foods.
  • Drink a large volume of the special cleansing solution and/or special oral laxatives recommended by your doctor. 
    • Split the solution dose.
    • Drink the first two liters on the evening before the exam.
    • Drink the second two liters four to six hours before the exam. This last step is critical to getting a really thorough cleansing.

“When preparing for a colonoscopy, it is extremely important to follow your doctor’s instructions to the letter,” says Marisa Mir, who had the exam and is a colon cancer survivor. “Any particle that may be left behind could possibly cover up something that requires immediate medical attention.”

Marisa admits that the preparation can sometimes be unpleasant or uncomfortable. “But it is only temporary,” she says. “And, very much worth it to know what might be happening inside your body.” 

Get a personalized prep plan from your doctor

doctor and patient
Talk to your doctor about what you can and can’t eat before the exam. Ask your doctor about what’s the best way to clean your colon.

If you generally have problems with constipation, discuss this with your doctor. Your doctor may suggest drinking magnesium citrate. That way you won’t be constipated on the day you begin the cleansing solution. Don’t take Metamucil®, and don’t eat foods with small seeds, like kiwi, cucumber or bread with sesame seeds. These foods can disrupt the cleansing process.

Remember to tell your doctor about any medications you’re taking. This includes aspirin products, non-steroidal anti-inflammatory medicines, arthritis medications, blood thinners, insulin and iron products.

Be sure to inform your doctor about any allergies you may have to medications. If you have diabetes, ask your doctor if you need to adjust your insulin or other drugs to control blood sugar.

MAKE AN APPOINTMENT: You can schedule an appointment for a colonoscopy, or other colon cancer exam, at MD Anderson. Call 713-563-5360 or request an appointment online.


© 2014 The University of Texas MD Anderson Cancer Center