Stop Colon Cancer Now Logo

Split-Dose Prep: Why Two Doses are Better than One

Jessica Francis

split-dose prep

A lot can change in ten years. Take, for instance, fashion trends. According to Cosmopolitan magazine, the top fashion trends of 2007 included popped collars, mini vests, sweatpants with writing across the rear, and Ugg boots paired with shorts. And if you think that sounds bad, try going back another 10 years. The hottest fashion trends of 1997 included wide leg jeans, overalls, shiny track jackets, and backpack purses.

Thank goodness those were all temporary, right?

Fashion isn’t the only thing that can change considerably over the course of a decade. Colonoscopies can too. And since most individuals only need to repeat screening colonoscopies once every 10 years, there’s a good chance that your next colonoscopy and bowel preparation will be a little different than your last one.

In recent years, the Standards of Practice Committee of the American Society for Gastrointestinal Endoscopy (ASGE) updated their guidelines for bowel preparation before a colonoscopy. These guidelines now recommend split-dosing the bowel prep solution. Rather than drinking a large volume of purgative solution the night before your procedure, the split-dose regimen allows you to drink half of your solution the night before your colonoscopy and the remaining half on exam day. This method is more easily tolerated by patients, and most importantly, it leads to more thorough examinations.

A randomized trial found that low-volume split-dose bowel preparation quadrupled the detection rate of sessile serrated polyps during a colonoscopy, compared to a low-volume, single-dose regimen taken the night before an exam. The study included 341 participants who were scheduled for an outpatient colonoscopy. All patients were given two liters of a bowel prep solution containing polyethylene glycol, sodium sulfate, sodium chloride, potassium chloride, sodium ascorbate and ascorbic acid. Participants in the single-dose group were instructed to drink their entire bowel prep solution the night before their procedure. Those in the split-dose group were instructed to drink half the solution the night before their colonoscopy and the other half on exam day.

Colonoscopy completion rates for both groups were quite similar, but researchers noted significant differences in the quality of bowel preparation and the rate of serrated polyp detection. Patients in the split-dose group had a 95.6 percent rating of good or excellent bowel prep, compared to a 85.5 percent rating in the single-dose group. Serrated polyp detection was 9.9 percent in the split-dose group, a rate nearly four times higher than the 2.4 percent rate in the single-dose group.

Researchers found no significant difference between the two study groups in terms of adenoma detection rate or other measures of adenoma detection such as size, number or location. However, the increased detection of sessile serrated polyps is significant. Sessile serrated polyps are flat, broad-based polyps that are more difficult to detect than conventional adenomas. If left untreated, these polyps have the potential to become cancerous.

Senior study author Carol Burke, M.D., vice chair of the Division of Gastroenterology and Hepatology at Cleveland Clinic, explained that some patients may not prefer the split-dose method due to concerns over lost sleep or the need to continue bathroom visits on the morning of their exam. However, several doctors and organizations stand behind the effectiveness of the split-dose regimen.

Joseph C. Anderson, M.D., associate professor at the Dartmouth College Geisel School of Medicine, in Hanover, N.H., said of the study results, “Split dosing versus a single dose the night before the exam should be part of the standard regimen for endoscopy practices to ensure adequate detection of conventional adenomas as well as serrated polyps. To ensure compliance, endoscopists need to reinforce the importance of adequate bowel cleansing to patients who may be reluctant to take split doses due to the potential loss of sleep” (Source: Gastroenterology & Endoscopy News).

Change can be a good thing – especially when it leads to more thorough colonoscopies. Talk to your gastroenterologist about the benefits of using a split-dose regimen for your next procedure. With a high-quality exam and a clean bill of health for the next 10 years, you just may find that your bowel prep solution isn’t so tough to swallow after all.


Related articles:

New Changes in Bowel Prep Mean Good News for Patients and Doctors

The Many Benefits of Split Dose Prep

comments powered by Disqus