Ensure Success with Colonoscopy Prep

Focused on Health - March 2010

by Adelina Espat

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

Many say that preparing for the colonoscopy is the worst part of the entire exam. But, it just so happens that it’s also the most important part.

 “If the prep is done right, it’s easier for your doctor to see not only big polyps but also flat polyps, which can be harder to spot if your colon is not completely clean,” says Gottumukkala S. Raju, 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.

READ ALSO: Who's more likely to get colon cancer?

“We really want to find those flat polyps because they tend to grow into cancer faster than any other polyp type,” Raju 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 stool that’s left. 

“I remember patients who did not properly follow their doctor’s instructions and went in for their colonoscopy with a semi-clean colon,” Raju says.

“One of two things happened – the doctor couldn’t see the insides of the colon clearly, so the patient had to redo the prep and come in for a repeat colonoscopy.  Or, even worse, the doctor missed a polyp during the exam—a hidden polyp with the potential to become cancer.”

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.

On the day before your exam:

• Eat plain cereal with milk for breakfast.
• Eat a light lunch consisting of soups without vegetables.
• Drink clear liquids only. 
• 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 clean.

“Preparing for a colonoscopy can be tough because you do get hungry,” says Marissa Mir, who recently had the exam. “It also can be uncomfortable because you have to stay near a restroom when you take laxatives and drink the solution.”   

“But it’s so important to clean out your system because if any particle is left behind, it could cover up polyps,” Marissa says. “So, it’s very important to follow your doctor’s directions.”

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

Get a personalized prep plan from your doctor

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 so that you are not constipated on the day you begin taking the cleansing solution. Do not take Metamucil® and do not eat foods with small seeds, such as kiwi, cucumber or bread with sesame seeds. These foods can disrupt the cleansing process.

Remember to inform your doctor about any medications you’re taking, particularly aspirin products, non-steroidal anti-inflammatory medicines, arthritis medications, blood thinners, insulin or iron products.

Most medications can be continued as usual, but some medications can interfere with the preparation or the examination. Be sure to mention to your doctor any allergies you may have to medications.  

If you have diabetes, ask your doctor if you need to adjust your insulin or other medicines to control blood sugar.