To explore the clinical efficacy of Tongbian Decoction（通便汤）in treating functional constipation patients with Qi and Yin deficiency type by regulating the brain-gut-microbiota axis signaling pathway and analyze its mechanism of action.

Seventy-four patients with functional constipation who visited the Department of Colorectal and Traditional Chinese Medicine of Dangshan County People´s Hospital from January 2023 to December 2023 were selected.They were randomly divided into a Western medicine group and a Chinese medicine group using a random number table method，with 37 patients in each group.The Western medicine group was treated with Pulucabili Tablets，while the Chinese medicine group was treated with Tongbian Decoction.The clinical efficacy，symptoms，psychological status and adverse reactions of two groups as well as the changes in gut microbiota and brain gut peptide levels before and after treatment were compared.

The effective rate in the Western medicine group was 64.86%（24/37），while that in the Chinese medicine group was 83.79%（31/37）. Compared with the Western medicine group，the effective rate of the Chinese medicine group was significantly higher（P<0.05）.According to the severity，the symptoms scored 0-3 points in order.After 4 weeks of treatment，the symptom scores of fecal morphology/type，defecation interval and difficulty of defecation in the Chinese medicine group were significantly lower than those in the Western medicine group（P<0.01）.After the intervention，the scores of Hamilton Anxiety Scale（HAMA）and Hamilton Depression Scale（HAMD）in Chinese medicine group were significantly lower than those in western medicine group（P<0.01）. Compared with those in western medicine group，the levels of serum 5-hydroxytryptamine（5-HT），vasoactive intestinal peptid（VIP）and neuropeptide Y（NPY）in Chinese medicine group were significantly lower with statistical significance（P<0.01）.There was no significant difference in the levels of Bifidobacterium，Lactobacillus or Faecalibacterium prausnitzii between the two groups before intervention（P>0.05）.After the intervention，the levels of Bifidobacterium，Lactobacillus and Faecalibacterium prausnitzii in the Chinese medicine group were significantly higher than those in the Western medicine group.The main adverse reactions of all patients during the intervention process were nausea，vomiting，loss of appetite，abdominal pain，diarrhea，dizziness and headache.There was no significant difference in the incidence of adverse reactions between the two groups（P>0.05）.

Tongbian Decoction has a good clinical effect in treating functional constipation by regulating the brain-gut-microbiota axis signaling pathway.It can improve the psychological status of patients，regulate the gut microbiota and serum levels of brain gut peptides such as 5-HT，VIP and NPY，and there is no increase in adverse reactions.