The effect of bile salts, i.e. bile acids, is mainly to promote the digestion and absorption of fats. 1. Bile acid can be used as an emulsifier to reduce the surface tension of fat, so that the fat can be emulsified into micro-droplets dispersed in the aqueous intestinal fluid, thus increasing the area of action of pancreatic lipase and promoting the decomposition and digestion of fat. 2. There is a layer of immobile water on the surface of the villi of small intestine, i.e. hydrostatic layer, the fat decomposition products are not easy to pass through the hydrostatic layer to reach the surface of the mucosa and be absorbed by the epithelial cells, while bile acid salt and fatty acid, monoacylglycerol, etc. can form the mixed microparticles, which are easy to pass through the hydrostatic layer to reach the surface of the intestinal mucosa, thus promoting the absorption of the fat decomposition products. It is recommended to seek prompt medical attention and early treatment under the guidance of a physician to avoid adverse effects.