Efficacy of macrogol 4000 plus electrolytes in bowel preparation for colonoscopy in patients with chronic constipation

Background: Chronic constipation is a significant factor in poor bowel preparation for colonoscopy. Macrogol 4000 plus electrolytes (Movicol, EA Pharma, Tokyo, Japan), containing polyethylene glycol (PEG) and electrolytes, have been used recently to treat patients with constipation. However, prospective studies on the use of macrogol 4000 for bowel cleansing for colonoscopy are lacking. This study aimed to investigate the efficacy and safety of macrogol 4000 in addition to PEG administered in patients with chronic constipation. Methods: This single-center, single-arm prospective study enrolled patients with chronic constipation who were scheduled to undergo colonoscopy. The primary endpoint was the proportion of good bowel preparation assessed using the Boston bowel preparation scale (BBPS) (6 or more points). The secondary endpoints were the time from when pPEG (MoviPrep, EA Pharma, Tokyo, Japan) was taken until colonoscopy could be started, amount of PEG taken, number of defecations, whether additional PEG doses were taken, and adverse events. Endoscopy-related endpoints included cecal intubation rate, insertion time, observation time, adenoma detection rate (ADR), and polyp detection rate (PDR). The tolerability of PEG and macrogol 4000 was assessed using a questionnaire. Results: Forty patients were included in the analysis. The median BBPS was 7 (range 3–9) and ≥ 6 points in 37 cases (92.5%). The median time until colonoscopy can be started was 210 min (90–360 min), the median volume of PEG taken was 1500 mL (1000–2000 mL), and the median number of defecations was 7 (3–20). No adverse events were observed. Fourteen patients required an additional dose of PEG. Cecal intubation was achieved in all cases, the median insertion time was 6.0 min (range 2.3–22 min), and the median observation time was 8.8 min (range 4.0–16.0 min). The ADR and PDR were 60.0% and 75.0%, respectively. A proportion of patients rated the tolerability of macrogol 4000 and PEG as 95.0% and 50.0%, respectively. Conclusions: Intake of macrogol 4000 in addition to PEG is effective and safe for colonoscopy in patients with chronic constipation. Clinical trial registration statement This study was registered in the UMIN-CTR database (UMIN-ID000038315).