Objective To explore the alterations of gut microbiota - short chain fatty acid metabolic axis in IBS-D rat model, and to explore the effect of sodium butyrate on this axis. Methods Seventeen Wistar rats were randomly divided into three groups. The IBS-D rat model was induced by 4% acetic acid enema combined with restraint stress. During the modeling period, sodium butyrate was injected intraperitoneally. The fecal flora of rats was detected by 16sRNA technology, and the fecal short chain fatty acid content of rats was detected by liquid chromatography mass spectrometry (LC-MS). Results Compared with the normal group, the weight of the model group was decreased, AWR score and fecal water content have a significant increase, the relative abundance of intestinal probiotics was decreased，while that of g-Blautia was elevated, the fecal acetic acid content was increased significantly, and the contents of butyric acid and valeric acid was decreased significantly in the model group. After drug intervention, compared with the model group, the weight of rats in the sodium butyrate group was increased, the AWR score and fecal water content was decreased significantly, the relative abundance of g-Blautia was decreased significantly, and the fecal butyric acid and valeric acid content was obviously increased. Conclusions Sodium butyrate can alleviate diarrhea and colon visceral hypersensitivity in IBS-D rats by improving the imbalance of gut microbiota - short chain fatty acid metabolic axis.