1. The pathogenic factors of diarrhea are external sensation, jungjishiljo, weakness of the spleen and stomach, improper diet, sinyanghueson, sueumyujang, liver Gi invades the spleen, uhhyuljeche. 2. The etiological causes of diarrhea are classified into pung, han, seo, seup, yul, sikjuk, ju, chiljung, damsul. Morphology of diarrhea are classified into yu, hwal, son, pok, goe, dongsul. 3. The etiological cause of diarrhea are closely related to the malfunction of the spleen, stomach and the related jang and bu's pathological alternation such as splees & stomach, large intestine, small intestine, liver, spleen, and kidney. 4. Diarrhea was mentioned in literatures not only as chronic Heohansung disorder, but also acute silyulsung disorder, based on hanyulheosil theory.