Improve patients' colonoscopy prep, or increase risk of missed polyps

Good prep for a colonoscopy could be the difference of life and death for a patient. Five percent of colon cancers can develop in patients who have had a colonoscopy because the procedure is not perfect. However, on-third of those cancers are due to poor prep. If done correctly, the prep may have prevented those colon cancers, says G.S. Raju, MD, FACG, FASGE, a professor in the department of Gastroenterology, Hepatology and Nutrition of Medicine at the University of Texas MD Anderson Cancer Center in Houston.

A study by physicians at Columbia University Medical Center in New York City found that when bowel preps are not good, physicians may miss 42% of all adenomas (polyps) and 27% of advanced adenomas, suggesting that suboptimal bowel preparation has a substantially harmful impact on the effectiveness of a colonoscopy.1 Therefore, healthcare institutions should work to make sure the steps to prepare patients for a colonoscopy are effective. Good preparation not only includes the proper steps, but education to make sure they are followed correctly.

At the University of Michigan Health System in Ann Arbor, the literature and research shapes the options patients have for prep. As a result, the institution's instructional sheets are rewritten as research uncovers best practice for prep, says Grace H. Elta, MD, a physician at the University of Michigan Internal Medicine Gastroenterology. Elta, along with a nurse educator and a nurse manager on the endoscopy unit, co-authored the prep instructions.

According to Raju, a quality improvement project helped shape prep instructions. A 16% poor prep rate among patients was reduced to 8% by going from a single dose, 4 L cleansing solution to a split dose. Patients prepare for the procedure by drinking a 2 L cleansing solution in the evening before their appointment and a 2 L solution the next morning. When laxatives were added to the prep process, the poor prep rate dropped to 2%, says Raju.

Once good prep instructions are in place how do you make sure they are followed?

"We are attuned to the fact that education is critical to the quality of the prep," says Elta.

Patients who come to the Gastroenterology Clinic at the University of Michigan meet with a nurse who goes over the instructions with the patient before providing a copy. During the educational session, the nurse emphasizes the importance of quality prep and how it impacts the effectiveness of the exam. Also emphasized is the importance of following the instructions completely, which includes drinking all the cleansing solution.

Some patients refuse to take the time to go over the instructions with the nurse, Elta says. Also, many patients are referred to the clinic by primary care physicians who provide the instruction sheets but might not have the time to discuss the preparation process.

Sometimes patients are compliant, but they might obtain only fair quality prep due to a sluggish gut, says Elta. In such cases, she writes on the report that the prep was only fair and the patient might need two-day prep when he or she has another colonoscopy.

Provide detailed instructions

Raju has several steps for educating his patients about the preparation for a colonoscopy. He refers them to the MD Anderson web site to view short videos made with the patient education office for YouTube. (For more information on these videos see resources, p. 99.) Also, written instructions created by the education department are provided.

Instructions need to be detailed, says Jane C. Frank, MPH, a senior health education specialist at the Patient Education Office of MD Anderson Cancer Center. Recently she worked with the director of the endoscopy clinic to create updated instructions for colonoscopy preparation for patients on blood thinners and those who are not on blood thinners. See instructions for colon prep.

Raju makes a telephone call to patients to review the instructions they have been given. He tells them that they will know they have accomplished good prep and that their colon is clean if they are able to see the bottom of the toilet following elimination once they have consumed all the solution. He also explains that without good prep, polyps can be missed.

To help patients achieve success, he tells them to drink the solution with a straw so it is siphoned to the back of the throat missing the taste buds on the tip of the tongue. He learned this trick from a patient. Also he advises patients to wear adult disposable underwear during the night if they are fearful of soiling the sheets and when driving to the clinic for the appointment, if they are traveling two hours or more, to avoid soiling their clothing.

If people are willing to go through the preparation process for a colonoscopy, healthcare practitioners need to provide the education for them to do it right, says Raju.

"If you educate people everyone will work hard to get the best results out of the ordeal they go through," he adds.


1. Lebwohl B, Kastrinos F, Glick M, et al. The impact of suboptimal bowel preparation on adenoma miss rates and the factors associated with early repeat colonoscopy. GIE 2011; 73:1,207-1,214.


For more information about educating patients on good colonoscopy prep or creating educational pieces, contact:

Grace H. Elta, MD, University of Michigan Internal Medicine Gastroenterology, Ann Arbor. E-mail:

Jane C. Frank, MPH, Senior Health Education Specialist, Patient Education Office, The University of Texas MD Anderson Cancer Center, Houston, TX. Telephone: (713) 563-8182. E-mail:

G.S. Raju, MD, FACG, FASGE, Professor, Department of Gastroenterology, Hepatology, and Nutrition of Internal Medicine, The University of Texas MD Anderson Cancer Center. Telephone: (713) 792-4283. E-mail: Web:

Online video colonoscopy preparation is available at Raju's web site: Click on "Patient Education." Short videos include "About Colon Cancer;" "About Colonoscopy;" and "Prepare for Colonoscopy."

To access the video on MD Anderson Cancer Center web site, go to In the middle of the page, under "Cancer Centers and Clinics," click on the drop-down arrow and select "Cancer Prevention Center." On the right navigation bar, under the "Related Topics" box, select "Cancer Screening Recommendations." In the "Multimedia" box to the right, the video title is listed under "Colonoscopy Information" in six parts.