Arrow-right Camera
The Spokesman-Review Newspaper
Spokane, Washington  Est. May 19, 1883

ASK THE DOCTORS: Reader needs colonoscopy but can’t drink prep solution

By Eve Glazier, M.D., , Elizabeth Ko and M.D. Andrews McMeel Syndication

Dear Doctor: Now that I’ve turned 50, I need to get a colonoscopy, but I just can’t drink that disgusting prep solution. I’ve tried three different times, but I wind up so nauseated that I can’t finish. Is there any other way to prepare?

Dear Reader: Let us reassure you that you’re not alone in your struggles with preparing for a colonoscopy. Many of our patients say that the procedure itself is a breeze compared to drinking the solution. However, the preparation phase , which thoroughly empties the intestines, is vital to a successful procedure. Alternatives do exist, but they don’t have the same effect, and therefore the results of the colonoscopy may not be as accurate or useful.

A colonoscopy is a procedure in which a gastroenterologist examines the inside of your colon and rectum using a long, flexible tube. Known as a colonoscope, it’s equipped with a lighted tip and a camera. A colonoscopy can reveal whether colon tissues are irritated or swollen, if polyps have formed, and whether cancer is present. When polyps are found, a small wire loop on the colonoscope can be used to remove them.

For the best view, the colon must be clean. In fact, the state of your colon is the most important variable in the exam. Unless every last vestige of fecal matter has been eliminated, it’s possible that polyps, which are small growths with the potential to become cancerous, or other abnormalities may be missed.

And here’s where the dreaded prep solution comes into play. Available under brand names like Golytely, Colyte, Nulytely and Trilyte, these are powders that consist of a laxative, along with essential electrolytes like potassium and sodium. You mix the prep powder with 4 liters of water and drink it according to your doctor’s orders. The laxative, along with the volume of water, empties and cleanses the bowel. The added electrolytes compensate for those you are losing. Because electrolytes are basically salts, the prep solution tries to compensate for the taste with the addition of super-sweet flavorings. The mix of the two , as you have found, is challenging.

An alternative is a low-volume prep solution that you mix with significantly less water. You still have to drink a full 4 liters of fluid prior to the exam, but other than the 2 cups or so of the low-volume prep solution, the rest of that 4 liters can be water or any other clear liquid.

But – and this is important – low-volume prep solutions won’t get the colon as clean. Also, there is the risk that your electrolytes can be sent out of balance. If there’s really no other way, then discuss the low-volume prep with your doctor. And if you’re willing to give traditional prep just one more go, try these tips:

Chill the solution well before drinking.

Sip it through a wide straw (it’ll go faster) placed far back on your tongue.

Alternate gulps of solution with sips of something that tastes good.

It’s not fun and it’s not easy, but it’s worth the investment because you’ll get the best results from your colonoscopy. And, remember: When it’s caught early, colon cancer can be successfully treated.

Send your questions to, or write: Ask the Doctors, c/o Media Relations, UCLA Health, 924 Westwood Blvd., Suite 350, Los Angeles, CA, 90095.