Objective To investigate the effect of Modified Renshen Wumei Decoction on the TLR4/MyD88/pNF?κBp65 signaling pathway and elucidate the potential mechanism by which this formula repairs the intestinal mucosal barrier in diarrheal rats. Methods Twelve rats were randomly selected from a total of 48 rats to serve as the blank control group （CK）， while the remaining 36 rats were used to establish a disease model via a compound method. After 14 days of model preparation， the rats were randomly divided into three groups： the model group （MC）， the western medicine group （MV）， and the traditional Chinese medicine group （MRWD）. Each of the four groups （including CK） received corresponding interventions for 7 days. The concentrations of serum diamine oxidase （DAO）， D?lactic acid （D?Lac）， interleukin?1β （IL?1β）， IL?6， IL?10， tumor necrosis factor?α （TNF?α）， mucin 2 （MUC2）， MUC4， MUC6， and colonic homogenate secretory immunoglobulin A （SIgA） were measured using ELISA. Additionally， the protein and gene expressions of colonic toll?like receptor 4 （TLR4）， myeloid differentiation primary response 88 （MyD88）， phosphorylated nuclear factor kappa?light?chain?enhancer of activated B cells p65 （pNF?κBp65）， occludin， claudin?1， and zonula occludens?1 （ZO?1） were analyzed by Western blot and RT?PCR. Results （1） Intestinal mucosal injury markers： Compared with the blank group， the serum levels of DAO and D?Lac in the model group were significantly increased （P < 0.05）. Compared with the model group， both the Chinese medicine group and Western medicine group significantly decreased the serum levels of DAO （P < 0.001）， while the traditional Chinese medicine group also significantly reduced the serum levels of D?Lac （P < 0.05）. There was no significant difference in the changes of DAO and D?Lac serum levels between the Chinese medicine group and Western medicine group （P > 0.05）. （2） Inflammatory indicators： Compared with the blank group， the model group exhibited significant upregulation of TLR4， MyD88， pNF?κBp65 protein and gene expression， as well as serum levels of IL?1β， IL?6， and TNF?α （P < 0.05）， along with a significant decrease in IL?10 serum levels （P < 0.05）. Compared with the model group， both the Chinese medicine group and Western medicine group significantly downregulated TLR4， MyD88， pNF?κBp65 protein and gene expression， as well as serum levels of IL?1β， IL?6， and TNF?α （P < 0.05）， and significantly upregulated IL?10 serum levels （P < 0.05）. There was no significant difference in serum levels of TLR4， MyD88， pNF?κBp65 protein， gene expression， and IL?1β， IL?6， IL?10， and TNF?α between the Chinese medicine group and Western medicine group （P > 0.05）. （3） Intestinal mucosal barrier factors： Compared with the blank group， the model group exhibited significant downregulation in MUC2， MUC6， SIgA content， as well as Claudin?1， ZO?1 protein and gene expression， and Occludin protein expression （P < 0.05）. Compared with the model group， both Chinese and Western medicine groups significantly upregulated the content of MUC2 and SIgA， as well as the protein and gene expression of Claudin?1 and ZO?1 （P < 0.05）. The traditional Chinese medicine group also significantly increased the content of MUC6 and Occludin protein expression （P < 0.05）. No significant differences were observed between the Chinese and Western medicine groups in terms of MUC2， MUC6， SIgA serum content， and Claudin?1 and ZO?1 gene expression （P > 0.05）. However， the Western medicine group showed better Claudin?1 protein expression than the Chinese medicine group （P < 0.05）， while the ZO?1 protein expression was higher in the traditional Chinese medicine group compared to the Western medicine group （P < 0.05）. Conclusion Modified Renshen Wumei Decoction exerts an intestinal mucosal barrier repair effect in diarrhea rats by modulating the TLR4/MyD88/pNF?κBp65 signaling pathway.