Low-Volume Bowel Prep Adequate in Hospitalized Patients

PHILADELPHIA — Low-volume bowel preparation is noninferior in adequacy to standard-volume prep in hospitalized patients undergoing colonoscopy, according to a study presented at the American College of Gastroenterology (ACG) 2024 Annual Scientific Meeting.

Patients who received MoviPrep (2L of polyethylene glycol and ascorbic acid) reported higher tolerability and willingness to repeat colonoscopy preparation in the future than those taking GoLYTELY (4L of polyethylene glycol and electrolytes). In addition, the rates of electrolyte abnormalities and acute kidney injury were low and similar between the two groups.

“Bowel preparation remains a challenge in the inpatient setting, where 20%-50% of all colonoscopies can have inadequate bowel preparation,” said lead author Karen Xiao, MD, assistant professor in the section of digestive diseases at Yale School of Medicine, New Haven, Connecticut.

Previous studies have indicated that low-volume (2L), split-dose preparations are noninferior to high-volume (4L), split-dose regimens, and patients generally prefer low-volume options, she said. However, the current standard of care for inpatients continues to include high-volume polyethylene glycol electrocyte lavage, which may be less tolerable.

“Similar to prior studies, our study supports that MoviPrep may be a suitable alternative to traditional high-volume bowel preparation in hospitalized patients undergoing colonoscopy,” she said.

In a single-blind, multi-site randomized controlled trial, Xiao and colleagues in the Yale–New Haven Health System randomly assigned inpatients undergoing colonoscopy to MoviPrep or GoLYTELY between January 2022 and July 2024. They excluded patients with prior small or large bowel resection, foreign body removal, or medical contraindications, such as obstruction, pregnancy, phenylketonuria, or glucose-6-phosphate dehydrogenase deficiency.

After bowel prep but before colonoscopy, patients took the Mayo Clinic Bowel Preparation survey. Colonoscopies were then recorded, and videos were scored by a single-blinded central reviewer. The primary outcome included the adequacy of bowel prep as defined by a Boston Bowel Preparation Scale score of 6 or higher, with each segment scoring 2 or higher.

In the final analysis, 202 patients received MoviPrep and 210 received GoLYTELY. In both groups, the average age was 62; about 60% were men; and 66% were White, about 22% Black, and 13%-15% Hispanic. About 65% of patients in both arms had an American Society of Anesthesiologists (ASA) score of 3, with another 20% in each group having an ASA score of 4, “reflective of a sicker inpatient population,” Xiao said.

Inpatient colonoscopy was indicated for gastrointestinal bleeding (55%), diarrhea (15%-20%), abnormal imaging (10%-13%), inflammatory bowel disease (4%), or other (35%-41%). Patients could have more than one indication for colonoscopy.

Overall, bowel preparation was scored as adequate in 111 patients with MoviPrep (55%) and 111 patients with GoLYTELY (52.9%), and was inadequate in 91 patients with MoviPrep (45%) and 99 patients with GoLYTELY (47.1%). With a rate difference of 2.1% and a P value of .007, MoviPrep was considered noninferior to GoLYTELY for adequate bowel preparation.

In terms of secondary outcomes, there wasn’t a significant difference in the length of hospital stay, with a median stay of 6 days. Similarly, there were no differences in the rates of adverse events, including acute kidney injury and electrolyte abnormalities, with rates ranging from 1% to 9%. MoviPrep patients were slightly more likely to need additional bowel prep but also had a slightly shorter time-to-colonoscopy.

Ease of Use Is a Plus

On the basis of the Mayo Clinic Bowel Preparation survey, there wasn’t a difference between the groups in how much bowel prep solution was left in the bottle. However, more than twice as many patients who took MoviPrep said the prep was “easy,” and more MoviPrep patients called it “acceptable,” whereas more GoLYTELY patients said prep was “somewhat difficult” or “very difficult.”

In addition, significantly more MoviPrep patients (49.7% vs 33.7%) said they were “mostly willing” to drink the same prep again if they needed another colonoscopy in the future, while more GoLYTELY patients said they were “somewhat willing” (44.7% vs 34.6%) or “not willing at all” (21.6% vs 15.7%).

“Bowel prep, particularly in hospitals, is important because we do it so often. When you think about what our patients in the hospital are going through, they’re very sick and often have multiple comorbidities, so how can we give them a bowel prep that is safe for them, easiest for them, easy for our nursing staff who are experiencing shortages, and as good as the traditional bowel prep,” said the session’s moderator, Amy Oxentenko, MD, professor of medicine and gastroenterologist at Mayo Clinic, Rochester, Minnesota.

“Here we’ve seen great data that we can provide half the volume of the prep, still get amazing results in terms of adequacy of preparation, and the patients had a better experience,” said Oxentenko, the incoming ACG president. “That’s important because they likely may need another colonoscopy in the future, and we would hate for the bowel prep in the hospital to potentially dissuade them from a future colonoscopy.”

Future studies could stratify patients on the basis of colonoscopy indication or patient history, including conditions such as chronic constipation or neurogenic bowel, where some patients may still need a high-volume prep, Oxentenko said.

“Also, in the hospital setting, we don’t always know when a patient is going to the endoscopy suite due to other patient cases that may get prolonged or pushed in,” she said. “So how do you time the second dose of the split dose in anticipation of when that patient will go to the endoscopy suite to maintain that great preparation with a smaller volume prep?”

The study was awarded the ACG Governors Award for Excellence in Clinical Research (Trainee). Dr Xiao and Dr Oxentenko reported no relevant disclosures.