Colonoscopy Prep: What You Need to Know

Getting a colonoscopy might not be at the top of your bucket list, but it’s an important screening tool to help identify colon cancer, the third most common cancer in the U.S. The American Cancer Society recommends that people begin getting colonoscopies at age 45 or sooner if they have unusual symptoms or risk factors, such as a family history or predisposing conditions.

The key to a successful colonoscopy is a thorough preparation, using laxatives to cleanse and empty your bowel to make it easier for your doctor to see inside your colon and rectum.

“The better the prep, the better the examination. If someone doesn’t prep well, we could miss polyps or other potentially dangerous findings,” says Thomas Lake, M.D., colon and rectal surgeon at Jersey Shore University Medical Center and Ocean University Medical Center.

Bowel prep can be unpleasant, but it’s important to follow your doctor’s instructions. Otherwise, you may need to reschedule or repeat the test—and face the preparation process again.

Choose Your Prep

There are several different laxatives available for colonoscopy prep. Most are liquid, though a pill option is also available. All require consuming a large volume of liquid, explains Dr. Lake. “Whether it's liquid medication or pills combined with drinking a lot of water, you're still consuming plenty of fluid either way,” he says.

The taste of the laxatives varies. Some have a slight lemon flavor, while others have no flavor but can be sweetened to improve the taste. If you get nauseated easily, tell your doctor so they can prescribe anti-nausea medication, Dr. Lake says.

Some colonoscopy preps are not suited for patients with kidney or cardiac conditions. Your doctor will individualize your prep to ensure it doesn’t impact your condition.

Plan for Success

Start planning your prep a few days before your colonoscopy. Make sure you have everything you need, including:

• The prep kit
• Approved flavorings or sweeteners to improve taste
• Clear liquids, such as clear broth, juices and popsicles
• Soft toilet paper or soothing wet wipes

Start reducing your fiber intake a few days before the procedure. Your doctor may also recommend avoiding certain foods, such as seeds and popcorn.

Time it Right

Stop eating solid food the day before your colonoscopy and switch to a clear liquid-only diet. Your doctor will direct you on when to take the laxative that day, depending on which one you’re using and the time of your colonoscopy.

Taking the laxative might not be pleasant, but here are some tips to make it easier:

• Drink it through a straw
• Keep it chilled
• Mix it with a flavoring or add a sweetener
• Follow it up with a tasty clear liquid, a candy, or a lemon wedge

After you take the laxative, you might experience cramps, gas and bloating. If you get nauseous, Dr. Lake recommends taking an hour off from drinking the prep. “We don’t want anyone to drink the prep too fast and then vomit,” he says.

Once the laxative starts working—anywhere from one to six hours—expect diarrhea and stay close to a bathroom.

It’s important to contact your provider if you’re experiencing problems such as vomiting or if the prep isn’t having a laxative effect. They can troubleshoot the situation with you and may prescribe additional medication.

“My preference is to prep early in the day because then we have time to come up with a Plan B if they have any trouble,” says Dr. Lake.

Stop drinking all liquids four hours before your procedure.

When you finish your bowel prep, your stools should be a clear or slightly greenish liquid. If they aren’t, tell your doctor.

Next Steps & Resources:

• Meet our source: Thomas Lake, M.D.
• To make an appointment with a colorectal surgeon or gastroenterologist near you, call 800-822-8905 or visit our website.
• Learn more about gastroenterology at Hackensack Meridian Health.

The material provided through HealthU is intended to be used as general information only and should not replace the advice of your physician. Always consult your physician for individual care.