Bowel preparation with linaclotide and 1 L polyethylene glycol plus ascorbic acid prior to colonoscopy in chronic constipated patients

Information on effective bowel preparation (BP) methods for patients with constipation is limited. We recently reported the efficacy of 1 L polyethylene glycol plus ascorbic acid (PEG-Asc) combined with senna for BP; however, this regimen was insufficient in patients with constipation. We hypothesized that the addition of linaclotide, which is approved for the treatment of chronic constipation, to 1 L PEG-Asc would yield results superior to those of senna in patients with constipation. This was a retrospective, single-center study that included outpatients with constipation who underwent BP prior to colonoscopy between March and December 2019 (receiving 1 L PEG-Asc with 24 mg senna) and between January and October 2020 (receiving 1 L PEG-Asc with 500 mg linaclotide). A total of 543 patients with constipation were included, of whom 269 received linaclotide and 274 received senna. The rate of inadequate BP was significantly lower (11% vs 20%, <i>p</i> &lt; 0.01) and the adenoma detection rate was significantly higher (54% vs 45%, <i>p</i> = 0.04) in the linaclotide group than in the senna group. Multivariate analysis revealed that the linaclotide regimen significantly reduced the risk of inadequate BP (odds ratio = 0.36, 95% confidence interval = 0.21–0.60, <i>p</i> &lt; 0.01). The linaclotide regimen significantly increased BP efficacy and the adenoma detection rate compared with the senna regimen without reducing tolerability and is therefore a promising new option for BP in patients with constipation.