The biliary system is the ductal structure that carries bile secreted by the liver to the duodenum and includes the intrahepatic and extrahepatic bile ducts, the gallbladder and the sphincter of Oddi. The biliary system is a complex structure that originates from the intrahepatic capillary bile ducts and its end joins the pancreatic duct. We can think of the biliary system as a “river” that gradually converges from small to large, with the source being the numerous intrahepatic capillary bile ducts that merge to form the interlobular bile ducts, which gradually form the two main streams, the left and right hepatic ducts. After the left and right hepatic ducts leave the liver, they converge into a main stem, the common hepatic duct, and then merge with the cystic duct to form the common bile duct, which eventually injects bile into the duodenal cavity. From this, we can also compare the common bile duct to the main stem of the Yangtze River, the left and right hepatic ducts are the tributaries of the Yangtze River, and the duodenal papilla is the “mouth of the Yangtze River”. The gallbladder is the “Dongting Lake” or “Poyang Lake” beside the “Yangtze River”, and the liver is the source of the “Yangtze River”. In about 85% of normal people, the end of the common bile duct joins with the pancreatic duct to form a common duct, which is controlled by the sphincter of Oddi and opens into the duodenal papilla. This is the anatomical basis for the interconnection of biliary and pancreatic diseases, such as biliary stones can cause pancreatitis and pancreatic disease can cause biliary obstruction. The biliary system has the function of secreting, storing, concentrating and transporting bile, and plays an important role in regulating the discharge of bile into the duodenum. About 3/4 of bile is secreted by hepatocytes and only 1/4 of the total bile is secreted by bile ducts. 800-1200 ml of bile is secreted daily by adults, which is an important digestive fluid, and its main components include bile acids, bile salts, cholesterol, lecithin and bile pigments, etc. If the ratio of these components changes, gallstones may be formed. Bile can combine with fat in food to form fat particles that can dissolve in water, and stimulate the secretion of pancreatic juice and activate the digestive enzymes in it to facilitate the absorption of fat, cholesterol and fat-soluble vitamins; bile can stimulate intestinal peristalsis and neutralize stomach acid, and bile salts in bile can also inhibit the growth and reproduction of pathogenic bacteria in the intestine. The secretion and discharge of bile are regulated by the hormones of the nervous system and endocrine, and most of the bile secreted by liver cells and bile ducts is stored in the gallbladder. If the discharge of bile from the “main stem of the Yangtze River” is blocked, it will definitely affect the liver in the “upper reaches of the Yangtze River”, causing changes in liver function, jaundice, and in severe cases, biliary cirrhosis, and if combined with biliary tract infection, it will cause acute obstructive purulent cholangitis. All of these conditions require surgical intervention to cure. The gallbladder is a cystic organ, connected only by the cystic duct to the common bile duct. The gallbladder acts as a “Dongting Lake” by the Yangtze River, regulating the “Yangtze River water level” and “drought and flood control”. The gallbladder contracts and discharges bile when the food consumed requires bile to help digestion, while the excess bile is stored and concentrated in the gallbladder during fasting. The concentration of bile in the gallbladder is often very high, and if the concentration is too high or the bile in the gallbladder cannot be emptied or replaced in time, gallbladder stones may form, and the stones formed will in turn affect the function of the gallbladder. Therefore, the changes of gallbladder function, gallbladder stones and bile composition in the gallbladder are causal, and the special structure of the gallbladder and the high concentration of bile composition in the gallbladder are the main reasons why gallbladder stones are difficult to be dissolved by oral medication.