目的 评估复方聚乙二醇电解质散（PEG）联合利那洛肽（Linaclotide，Lin）在老年便秘患者肠道准备中的有效性和安全性。 方法 采用前瞻性、随机对照临床试验设计。纳入行结肠镜检查的老年便秘患者90例，随机分为3组（各30例）：PEG-3L组、PEG-3L + Lin组和PEG-2L + Lin组。主要观察指标为波士顿肠道准备量表（BBPS）评分，次要指标包括不良反应发生率、全结肠镜检查完成率、退镜时间及息肉检出率。采用独立样本t检验和χ²检验进行统计分析。 结果 PEG-3L + Lin组BBPS评分显著高于PEG-3L组和PEG-2L + Lin组（P < 0.001），PEG-2L + Lin组评分亦优于PEG-3L组（合格率90.0% vs. 76.7%，P = 0.008）。PEG-2L + Lin组耐受性最佳，不良反应发生率最低。PEG-3L组退镜时间长于两联合组（P < 0.05），3组息肉检出率差异无统计学意义。 结论 PEG联合利那洛肽可显著提高老年便秘患者肠道清洁效果，其中PEG-2L + Lin方案在保证清洁度的同时兼具更优安全性和耐受性，适合临床推广。

Objective To evaluate the efficacy and safety of polyethylene glycol electrolyte powder （PEG） combined with linaclotide （Lin） for bowel preparation in elderly constipated patients before colonoscopy. Methods In this prospective， randomized controlled trial， 90 elderly patients with constipation undergoing colonoscopy were recruited at our hospital from June 2022 to December 2023. Participants were randomly assigned to three groups （n = 30 each）： PEG-3L alone， PEG-3L + Lin， and PEG-2L + Lin. Primary outcome was Boston Bowel Preparation Scale （BBPS） score and secondary outcomes included adverse event rates， colonoscopy completion rate， withdrawal time， and polyp detection rate. Statistical analysis was performed using independent t-tests and chi-square tests. Results The PEG-3L + Lin group achieved significantly higher BBPS scores than both PEG-3L alone and PEG-2L + Lin groups did （both P < 0.001）. The PEG-2L + Lin group also outperformed the PEG-3L alone group in cleansing efficacy （90.0% vs. 76.7%， P = 0.008）. The PEG-2L + Lin group demonstrated the best tolerability and lowest adverse event rate， the PEG-3L group had the longest withdrawal time （P < 0.05）， but the three groups showed no significant difference in polyp detection rates. Conclusion PEG combined with linaclotide significantly improves bowel cleansing in elderly constipated patients. PEG-2L + Lin regimen provides optimal balance between efficacy， safety， and tolerability， making it a preferable choice for this population.