Crohn"s disease and ulcerative colitis are two kinds of nonspecific inflammatory bowel diseases with frequent morbidity. Due to their unclear etiology, the two diseases can be clinically controlled by symptomatic treatment with limited effects, and often the prognosis is frequently poor. In order to find out the main cause, based on the common characteristics of these two diseases, combined with the diseases caused by other bile acids or their salts, this paper concludes that the main cause the overloaded primary bile salts in the intestine that corrodes the intestinal mucosa, and the minor cause is associated with the secondary bile salts. Afterwards, due to the abundant colon bacteria, infection happens, and flora imbalance and immune imbalance occur. Because the liver, where the bile comes from, is Mu, the small intestine is Huo, and the colon is Jin, the occurrence of this disease can also be summarized as "Mu Huo corroding Jin salts entering the intestine were also analyzed and a new treatment strategy was proposed.