Split-dose, low-volume bowel preps are better at detecting sessile serrated polyps than single dose preps

Liz Meszaros, MDLinx

Digestive Disease Week® (DDW)

San Diego, California, United States | May 21-24, 2016


San Diego, May 22, 2016—A low-volume, split-dose (SD) bowel preparation (BP) increased the detection rate of sessile serrated polyps by 4-fold compared with a single dose BP (S) given in the evening, according to researchers here at Digestive Disease Week 2016. In addition, researchers also found that this SD preparation significantly improved colon cleansing over evening S BP.

Take-home messages

  • Detection rates of sessile serrate polyps were increased by 4-fold with a low volume, split-dose bowel preparation compared to an evening single dose bowel prep.
  • A split-dose bowel preparation may significantly improve colon cleansing compared with single-dose bowel preparation.

“This study was part of a larger study assessing patient inconvenience related to split dosing compared to single dosing of bowel preparations. As a consequence of that, we also looked at outcomes involved in following the preparation as far as bowel cleanliness and polyp detection rates,” related lead author Nicholas Horton, MD, internal medicine, Cleveland Clinic Foundation, Cleveland, OH.

Dr. Horton and colleagues conducted this study in 341 patients undergoing colonoscopy (mean age: 54 ±14 years; 55% female) to compare polyp detection rates in S and SD BPs. The included patients scheduled for outpatient colonoscopy, and randomized them to S the evening before (n=168) or SD (½ dose in the evening and ½ dose the day of colonoscopy; n=173) with 2 liters of BP comprised of polyethylene glycol, sodium sulfate, sodium chloride, potassium chloride, sodium ascorbate, and ascorbic acid. They collected data on polyp number, size, location, and quality of colon cleansing and colonoscopy completion. Using pathology reports, they also recorded polyp histology, and used Kruskal-Wallis or X2 tests to compare polyp detection differences between the two regimens. The only difference between the arms was in the incidence of cirrhosis of the liver, with age, gender, and major comorbidities being similar.

Morning colonoscopies were performed in 81% of S and 68% of SD patients (P=0.007). In 85.5% of S patients, excellent or good preparation was documented, compared with 95.6% of SD patients; and with cecal intubation, colonoscopy completion rates were similar (99.4% vs 98.8%, respectively; P=0.87). Dr. Horton and colleagues found no between-arm differences in polyp or adenoma detection rates, location, size, or number of polyps.

Dr. Horton and colleagues did find a significantly greater detection rate of sessile serrated polyps in the SD arm compared with the S arm (9.9% vs 2.4%, P=0.004).