The incidence of diarrhea-predominant irritable bowel syndrome (IBS-D) remains high, with microRNA-mediated intestinal barrier dysfunction, visceral hypersensitivity, low-grade inflammation, and dysbiosis playing significant roles in its pathogenesis. Studies found that traditional Chinese medicine can treat IBS-D by directly or indirectly targeting miRNA to regulate multiple pathways and targets in a coordinated manner. This article systematically reviews the involvement of miRNA in the pathogenesis of IBS-D and the progress of traditional Chinese medicine interventions. It explores the relationship between traditional genetics, epigenetics, and the Chinese medicine concepts of "kidney" and "spleen" in terms of congenital and acquired interactions from a molecular biology perspective. This provides a reference for exploring the micro-material basis of traditional Chinese medicine's Zang-Xiang theory and offers new ideas and methods for the effective treatment of IBS-D with traditional Chinese medicine.