Splitting dosage of colonoscopy prep solution improves polyp detection

For colonoscopy to be effective, adequate bowel preparation is critical. The problem is that the volume of bowel preparation solution necessary to be ingested before the procedure tests a patient's tolerance and often can lead to noncompliance.

However, researchers recently have found that the use of split-dose bowel preparations (SDP) for colonoscopy increases both polyp and adenoma detection rates, according to a study published last month in the journal Gastrointestinal Endoscopy.

According to the authors, led by Suryakanth Gurudu, M.D., of the Mayo Clinic in Scottsdale, Ariz., SDP also increased the overall quality of the preparation, as well as the patient compliance rate.

The researchers conducted a retrospective study of 4,975 persons undergoing screening colonoscopy before (3,560 patients) and after (1,615 patients) after the implementation of SDP.

With SDP, patients are instructed to avoid eating a high-fiber diet for two days before drinking the polyethylene glycol (PEG) bowel preparation solution, and to only drink water the day before the procedure. With four-liter PEG solutions, the patients were instructed to drink two or three liters the night before the procedure, and the remainder at least four hours before the colonoscopy was scheduled.

The researchers found that with SDP, adenoma detection rates increased from 26.7 percent to 31.8 percent, while polyp detection rates increased from 44.1 percent to 49.5 percent. They also determined that bowel preparations improved significantly, as did the colonoscopy completion rate (from 93.5 percent to 95.5 percent).

"In our study, we have demonstrated, for the first time to our knowledge, that system-wide implementation of a split-dose preparation for colonoscopy significantly improves both polyp detection rates and adenoma detection rates as well as improves the quality of the preparation and colonoscopy completion rates," Gurudu said, according to an announcement. "These results confirm the benefit of split-dose preparations and the importance of bowel preparation in the detection of colon polyps."

Douglas Rex, M.D., Professor of Medicine and Director of Endoscopy in the Division of Gastroenterology & Hepatology at Indiana University Medical Center, wrote recently in Journal Watch Gastroenterology that the results of the study suggest SDP should be the "standard of care."

For more:
- see the article abstract in Gastrointestinal Endoscopy
- read the commentary in Journal Watch Gastroenterology (subscription required)