A novel ultra-low volume regimen combining 1 L polyethylene glycol and linaclotide versus 2 L polyethylene glycol for colonoscopy cleansing in Low-Risk individuals: A Randomized Controlled Trial

Open AccessPublished:December 23, 2022DOI:
      This paper is only available as a PDF. To read, Please Download here.


      Background and aims

      The single dose of 2L polyethylene glycol (PEG) has shown high cleaning efficacy and tolerability in low-risk patients. However, the dosage of this regimen is still challenging for many patients. We investigated the efficacy and tolerability of a novel ultra-volume regimen using 1L PEG and linaclotide (1L PEG+L) versus single dose of 2L PEG in low-risk patients.


      In this prospective, randomized, observer-blinded, multicenter study, low-risk adult patients scheduled for colonoscopy were enrolled and randomized (1:1) to receive 1L PEG+L or 2L PEG regimen. The primary outcome was the effectiveness of bowel cleansing according to the Boston Bowel Preparation Scale (BBPS). Secondary outcomes included cecal intubation rate, cecal insertion time, withdrawal time, polyp detection rate (PDR) and adenoma detection rate (ADR), tolerability, adverse events, and willingness to repeat bowel preparation. The full analysis set (FAS) and per-protocol set (PPS) were used for statistical analyses.


      A total of 548 patients comprised the FAS while 522 patients comprised the PPS. Non-inferiority on adequate bowel cleansing of 1L PEG+L vs 2L PEG was established both in FAS (90.5% vs 91.6%, P =0.644) and PPS (90.3% vs 92.4%, P =0.390). There were no significant differences with regard to the total and each segment scores of BBPS, cecal intubation rate, cecal insertion time, withdrawal time, PDR and ADR (all P > 0.05). However, patients in 1L PEG+L group reported less nausea (7.7% vs 17.1%, P <0.01), vomiting (4.0% vs 10.9%, P <0.01) and had a higher willingness to repeat (95.2% vs 82.2%, P <0.01).


      1L PEG+L regimen was not inferior to 2L PEG on colon cleansing with better tolerability and higher willingness to repeat in low-risk population.

      Graphical abstract

      Key words