Low-Volume, Same-Day Prep Gets Job Done for Colonoscopy

— Study shows similar efficacy between split­-dosing and same­-day bowel preparations

MedicalToday

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SAN DIEGO -- Low volume, same-day polyethylene glycol (PEG) colonoscopy preparation resulted in similar bowel cleanliness compared with low- and high-volume split-dose PEG solutions, researchers said here.

Specifically, patients who received same-day low-volume PEG (2L) given on the morning of the colonoscopy had bowel cleanliness that was comparable to patients who received split- dose low volume PEG (1L+1L) + bisacodyl (15mg) or split-dose high volume PEG (2L + 2L), reported Alan Barkun, MDCM, of McGill University Health Center in Montreal, and colleagues.

In addition, patients who received the same-day low volume prep had a much greater willingness to repeat the cleanse than the split-dose high-volume patients, they reported at the study, presented at the annual Digestive Disease Week.

The study is part of the , the purpose of which is to compare diet, the type of bowel preparation, and time of colonoscopy, in order to determine whether one method is superior.

While there has been extensive research in this area, previous reports suggested that from 10%-25% of patients have inadequate colon cleaning on the day of colonoscopy. Split-dose preparation has been shown to deliver superior cleanliness, but Barkun and colleagues suggested that the evidence is still lacking regarding how high-volume compares to low-volume solutions.

In this trial (one of a number of trials involving outpatients in 10 Canadian hospitals), 1,750 patients were randomized into one of three groups stratified by volume of PEG (2 or 4 L) and timing (split or same day) of delivery -- LowSame, LowSD, and HighSD.

The LowSame group received 2 liters of solution 4 to 5 hours before colonoscopy, while the LowSD and HighSD groups received 2 and 4 liters of solution, respectively, as a split dose (half delivered the day before colonoscopy and the other half the day of).

The average age of the study participants was 56.3; 54.4% were female.

Barkun and colleagues found that adequate bowel cleanliness was not significantly different between groups:

  • LowSame: 90.5%
  • LowSD: 87.9%
  • HighSD: 92.2%
  • HighSD and LowSD combined: 90.1%

In addition, they found that bowel cleanliness was independent of diet (clear liquid vs low residue).

While a willingness to repeat the bowel cleanse was similar between the LowSame and LowSD groups (91.0% vs 92.5%), the difference between the LowSame and HighSD (91.0% vs 68.9%) and LowSD and HighSD combined groups (91.0% vs 81.2%) was much greater.

Endoscopic quality markers, including adenoma detection rate, cecal intubation rate, and withdrawal time met quality standards and were similar between groups.

"A good bowel preparation is essential for a high quality colonoscopy, while a poor preparation results in missed lesions and provides false reassurance," Gautam Mankaney, MD, of the Cleveland Clinic, told . "As providers, we know that the bowel preparation is a difficult part of the procedure, if not the most difficult, and reasons include the quantity of bowel preps and strict adherence to a clear liquid diet."

Mankaney, who was not involved with the study, said the research by Barkun's group adds to the literature by demonstrating that half the standard prep volume, as well as a liberalized diet that includes low residue (solid and liquid) foods, does not impact the quality of bowel preparation.

"As expected, patients who received the lower-volume preps were more likely to repeat the same regimen than the high-volume preps," Mankaney said. "This research is important because as part of a community colon cancer screening program, more individuals are likely to complete their bowel preps without compromising the ability of the endoscopist to perform a high quality colonoscopy."

Disclosures

Barkun disclosed support from and relevant relationships with ATGen, Boston Scientific, Cook, and Pendopharm. Co-authors disclosed multiple relevant relationships with industry.

Primary Source

Digestive Disease Week

Barkun A, et al "The Bowel Cleansing National Initiative (BClean): A Low-Volume Same-Day Polyethylene Glycol (PEG) Preparation Versus Low-Volume Split-Dose PEG with Bisacodyl or High-Volume Split-Dose PEG Solution" DDW 2019; Abstract Mo1068.