To explore the medication experience and rules of prestigious veteran traditional Chinese medicine(TCM) doctors in treating diarrhea.Methods:Traditional Chinese Medicine Inheritance Support System(TCMISS) was used as the data source.All relevant cases since inception of the platform were searched using the western medical term “diarrhea”.Data mining software was used for frequency statistical analysis，association rule analysis，systematic clustering，factor analysis，and complex network topology analysis of the selected prescriptions.Results:A total of 131 prescriptions and 177 drugs were retrieved.The prescriptions mainly consisted of deficiency-tonifying drugs，heat-clearing drugs，exterior-releasing drugs，qi-regulating drugs，urination-promoting and dampness-draining drugs，and astringent drugs.The drugs were mainly warm，pungent，sweet，and bitter，and acted on the liver meridian，lung meridian，spleen meridian，and stomach meridian.Association rule analysis revealed 104 rules，with 37 rules involving four drugs.Factor analysis identified nine common factors，and systematic clustering resulted in seven major categories.Foundational prescriptions included Sijunzi Decoction，Shenling Baizhu Powder，Shaoyao Gancao Decoction，Zuojin Pills，Banxia Xiexin Decoction，Gegen Qinlian Decoction，and Ershen Pills.Complex network analysis identified key drugs，such as Atractylodis Macrocephalae Rhizoma，Glycyrrhizae Radix Et Rhizoma，Paeoniae Radix Alba，Poria，Citri Reticulatae Pericarpium，Codonopsis Radix，and Coicis Semen.Conclusion:Prestigious veteran TCM doctors follow the theories in the Huangdi's Internal Classic(Huang Di Nei Jing) when treating diarrhea，emphasizing the principles of eliminating dampness，warming yang，and consolidating root to check diarrhea.However，the attention given to the small intestine is not sufficient and requires further research.