Lactulose Combined With PEG for Effective and Safe Bowel Preparation Before Colonoscopy: A Meta-Analysis

To compare the efficacy of polyethylene glycol electrolyte (PEG) combined with lactulose versus PEG alone in bowel preparation quality for colonoscopy.

The protocol for this systematic review was registered with PROSPERO (CRD420251035139). Comprehensive literature searches were conducted across multiple databases, including PubMed, Embase, Cochrane Library, Web of Science, China National Knowledge Infrastructure (CNKI), Wanfang Data, and VIP. RevMan 5.4 software was employed to assess differences between the two groups regarding the rates of excellent bowel preparation, willingness to undergo repeat examination, incidence of adverse reactions, and adenoma detection rates.

Sixteen eligible studies, encompassing 2468 participants, were included in the analysis. Meta-analysis demonstrated that the combination of PEG and lactulose was significantly more effective than PEG alone in bowel cleansing (OR = 3.57, 95% CI: 2.75-4.63, p < 0.001, I ² = 0% for efficacy; SMD = 0.38, 95% CI: 0.26-0.50, p < 0.001, I ² = 45% for BBPS scores; SMD: Standard Mean Difference; BBPS: Boston Bowel Preparation Scale). This combination also led to a lower incidence of adverse events, including vomiting (OR = 0.54, 95% CI: 0.36-0.82, p = 0.004), abdominal pain (OR = 0.54, 95% CI: 0.36-0.80, p = 0.003), and abdominal bloating (OR = 0.53, 95% CI: 0.38-0.75, p < 0.001), compared with PEG alone. Furthermore, PEG plus lactulose significantly improved the detection rate of intestinal adenomas (OR = 2.57, 95% CI: 1.74-3.79, p < 0.001). However, no significant differences were observed in the incidence of nausea (OR = 0.69, 95% CI: 0.88-0.99, p = 0.05) or willingness to repeat the examination (OR = 1.31, 95% CI: 0.51-3.36, p = 0.58).

The combination of PEG and lactulose significantly enhances bowel cleansing efficacy, increases adenoma detection rates, and reduces the incidence of adverse reactions. This regimen is recommended for bowel preparation prior to colonoscopy.