This paper aims to clarify the theory of Chinese medicine for treating infant diarrhea by analyzing Professor Lan Shu’s three representative cases of treating cold diarrhea, damp heat diarrhea, spleen diarrhea, and spleen and kidney deficiency diarrhea in infants with Huoxiang Zhengqi powder addition and subtraction, Gegen Qinlian decoction, Qiwei Baizhu powder addition and subtraction, and Fuzilizhong decoction. Due to the characteristics of the etiology and pathogenesis of infant diarrhea, Chinese medicine has a unique advantage in treating ...