Are personalized tongxie formula based on diagnostic analyses more effective in reducing IBS symptoms?-A randomized controlled trial.

•All the existing clinical studies on the herbal treatment of IBS used a same formula, or “standardized CHM (Chinese herbal medicine) formulation” for all patients.•The outcomes of the some subpopulations may be different from those of the entire population, indicating that personalized formulas are important to achieve optimal outcomes•The active ingredients identified in tongxie relieve IBS symptoms simultaneously through multiple mechanisms that well match those of the conventional IBS medications and non-pharmacological approaches (Table 3; Fig. 3).•The active ingredients identified in this study can be the candidates for developing new IBS drugs; and the innovative mechanisms identified in this study may be used to manage IBS.