H Xu et al. Journal of Gastroenterology and Hepatology; 2024: https://doi.org/10.1111/jgh.16734. Application of linaclotide in bowel preparation for colonoscopy in patients with constipation: A prospective randomized controlled study
Methods: In this prospective, single-center, randomized controlled trial, 322 participants (18-75 yrs) were divided into two groups: a 3-L PEG + 870-μg linaclotide group (administered as a single dose for 3 days) and a 4-L PEG group. All enrolled patients had constipation as defined by the Rome IV criteria (fewer than three bowel movements per week with associated symptoms such as straining and hard or lumpy stools).
Linaclotide dosing: One 290-μg linaclotide capsule 30 min before the first meal for 3 days leading up to the colonoscopy, but not on the day of the procedure itself
Key findings:
- The 3-L PEG + linaclotide group showed significantly higher rates of adequate and excellent bowel preparation than the 4-L PEG group (89.4% vs 73.6% and 37.5% vs 25.3%, respectively; P < 0.05).
- Boston Bowel Preparation Scale (BBPS) score in the linaclotide group was significantly higher than that in the 4-L PEG group.
- Adverse effects like nausea and vomiting were less common in the linaclotide group compared to the 4-L PEG group. Nausea was noted in 10% of linaclotide group compared to 24.5% in the 4-L PEG group. vomiting occurred in 5% and 19.5% respectively. Overall, adverse effects were 24.4% compared to 41.5% respectively.
- The cecal intubation rate was 87.5% in the linaclotide group and 81.8% in the 4-L PEG group, which indicated a higher trend in the linaclotide group. Both groups had a lower cecal intubation rate than the 90% benchmark rate and could be related to the underlying constipation.

My take: In patients with constipation, linaclotide with 3L PEG resulted in a better cleanout than a standard 4L PEG prep. Combination laxatives as part of the prep should be considered in those with underlying constipation.
This study would be hard to replicate in children as very few children with constipation need a colonoscopy. It is possible that the addition of linaclotide would improve cleanouts even in children without constipation. Other studies showing linaclotide can help with cleanouts in the general population include the following:
- Zhang M, et al. Eur. J. Gastroenterol. Hepatol. 2021; 33: e625–33.
- Tao T, et al. Chin. J. Dig. 2022; 42
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