Abstract: Objective To evaluate safety and efficacy of linaclotide combined with polyethylene glycol(PEG) for bowel preparation. Methods A total of 612 patients from Department of Gastroenterology at the Affiliated Hospital of Qingdao University for colonoscopy examination from January to June 2023 were selected. They were divided into group 1(1 L PEG+2 L PEG), group 2(linaclotide+2 L PEG) and group 3(1 L PEG+linaclotide+1 L PEG) by random number table method, with 204 cases in each group. The Ottawa Bowel Preparation Quality Scale(OBPS), the insertion time of colonoscopy, the time of the first defecation, the frequency of defecations, the occurrence of adverse effects and patients' tolerability were compared among the three groups. Results A total of 601 patients completed bowel preparation and accepted colonoscopy. Group 1 exhibited no statistically significant differences to group 2 with regards to OBPS and insertion time. However, Group 2 demonstrated a shorter duration for the time of the first defecation in comparison to both group 1 and group 3(P＜0.05). Group 1 displayed a higher frequency of defecations as compared to Group 2 and Group 3(P＜0.05) . The incidence of adverse reactions was significantly lower in group 2 and group 3 than in group 1(P＜0.05). The overall tolerance score of patients in group 1 was lower than that in group 2 and group 3(P＜0.05). Conclusions The effect of combining 2 L PEG with 290 μg of linaclotide for bowel preparation before colonoscopy is similar to that of 3 L PEG. It can reduce the incidence of adverse reactions and patients exhibit good tolerance. For patients who are intolerant to a single high-dose administration of PEG, they need divided-dose regimen of 2 L PEG in combination with linaclotide.

Key words: linaclotide, bowel preparation, polyethylene glycol, colonoscopy