Zhang, X.; Chen, Y.; Chen, Y.; Zhu, W.; Tang, C.; Lamm, S.; Li, L. Polyethylene Glycol Combined With Lactulose Has Better Efficacy Than Polyethylene Glycol Alone in Bowel Preparation before Colonoscopy: A Meta-Analysis. Clinics 2023, 78, 100172. https://doi.org/10.1016/j.clinsp.2023.100172.