OBJECTIVE: This study aimed to investigate the PAR-2/TRVP1-based mechanism of steaming umbilical cord therapy with Chinese Herbal Medicine (SUCT-CHM) in IBS-D rat models. METHODS: Sixty-two IBS-D modeled rats were established, and were randomly assigned to the control group (n = 31) and the experimental group (n = 31). The model group did not receive intervention measures, and the experimental group was treated with SUCT-CHM. After 14 days of intervention, the two groups of rats were compared in terms of body weight, gastrointestinal function, Bristol stool score, wet/dry weight ratio of rat stool, and abdominal withdrawal reflex scores. The transient receptor potential vanilloid receptor 1 (TRPV1), protease-activated receptors-2 (PAR-2), calcitonin gene related peptide (CGRP) and Substance P (SP) protein expression were detected using ELISA. RESULTS: After 14 d of intervention, compared to the control group, the rats in the experimental group showed a significant increase in body mass indexes ( < 0.05); decreased Bristol stool scores ( < 0.05); less stagnation of the intestinal contents and greater intestine propulsion rate ( < 0.05), lower wet/dry weight ratio of rat stool ( < 0.05), abdominal withdrawal reflex scores ( < 0.05) as well as PAR-2, TRVP1, CGRP and SP expression levels ( < 0.05). CONCLUSION: SUCT-CHM was effective in treating IBS-D in rats. It improved gastrointestinal function and reduced visceral hypersensitivity in rats possibly via the PAR-2/TRVP1 pathway.