The gallbladder is an important digestive organ in the human body, which not only has the functions of storage, concentration and excretion (contraction), but also plays an important role in regulating the pressure of the bile ducts inside and outside the liver, and has important secretory and immunological functions. First, the gallbladder’s bile storage function: when a person is hungry (i.e., during non-digestion), bile is stored in the gallbladder and then discharged from the gallbladder when digestion is needed, so the gallbladder is called the “bile warehouse”. It also serves as a cushion for the pressure of the bile duct. The liver secretes 800-1000ml of bile every day, most of which is concentrated and stored in the gallbladder. Most of the water and electrolytes in the golden-yellow alkaline liver bile are absorbed by the gallbladder mucosa and returned to the blood, leaving the active ingredients in the bile stored in the gallbladder, which turns into brown or dark green weakly acidic gallbladder bile. Bile excretion function of the gallbladder: Bile excretion is regulated by body fluid factors and the nervous system, after eating 3-5min, the content of cholecystokinkinin (cholecystokinkin) increases, cholecystokinkin has the role of contracting the gallbladder and diastolic lower bile duct and oddi sphincter, gallbladder contraction can produce 2.94Kpa of internal pressure, prompting bile excretion to the duodenum, to help The bile is discharged to the duodenum to help the digestion and absorption of fat, and at the same time, the bacteria in the bile duct are also discharged together with the bile. Generally speaking, the gallbladder can be emptied after half an hour of eating fat. However, when the gallbladder is inflamed or the oddi sphincter is dysfunctional, the bile discharge becomes obstructed, the bile is stagnant and the solid components are precipitated, which becomes one of the causes of polyps or stones. The secretion function of gallbladder: The mucous membrane of gallbladder secretes about 20ml of mucus substance every hour, mainly mucin, which can protect and lubricate the mucous membrane of gallbladder from the dissolution of bile and make the bile pass through the cystic duct easily. When the bile duct is obstructed, bilirubin in bile is absorbed, mucus secretion by the gallbladder mucosa increases, and the liquid accumulated in the gallbladder is colorless and transparent, which is called “white bile”. The gallbladder with the accumulation of “white bile” is called hydronephrosis. When the gallbladder is inflamed and obstructed, the gallbladder can also secrete calcium. Another important function of the gallbladder is to regulate the pressure balance in the bile ducts. When 800-1000 cc of bile is produced in the liver every day and continuously discharged into the gallbladder and extrahepatic bile ducts, and a certain pressure is maintained, the regulation of the gallbladder is an important factor. The gallbladder can hold and concentrate more bile during increased pressure in the intra- and extrahepatic bile ducts and maintain a normal pressure balance in the bile ducts. When the gallbladder is removed, the role of regulating pressure balance disappears, however, the bile secreted by the liver does not decrease, but all the bile must be discharged into the duodenal cavity through Oddi’s opening every day, at which time the party feels that the opening is narrow and the excretion is not smooth. Inevitably, compensatory dilatation of the common bile duct occurs over time. The dilated common bile duct often turns the beak-like end into a rounded shape, at which time the bile flow eager to be discharged becomes a vortex, in the shape of a whirlpool, the latter being one of the important theories of gallstone formation vortex theory. This phenomenon is very easy to form common bile duct stones. Clinical practice also proves this. People often see a history of cholecystectomy when receiving patients with acute obstructive jaundice. Among 795 cases of common bile duct stones at Peking University First Hospital (confirmed by ERCP and EPT), the group of resected gallbladder cases was significantly higher than the group of unresected gallbladder (425:370) with significant statistical significance. Thus, cholecystectomy often results in compensatory dilatation of the common bile duct and an increased incidence of common bile duct stones. Similarly, because the gallbladder has an important role in regulating the internal pressure of the bile duct, patients who lose the organ of the gallbladder lose the balance of pressure in the bile duct, the pressure increases, and the sphincter of Oddi loses the regular pressure regulation of the gallbladder, and a regulatory disorder occurs, resulting in post-cholecystectomy syndrome. Sixth, the gallbladder has important immune functions: the gallbladder not only has storage, concentration and contraction functions; but also has secretion and immune functions. The gallbladder can secrete 20 ml of white liquid every day, which, according to scientific experiments, is the immunoglobulin (IgA) secreted by the lamina propria of the gallbladder mucosa. Moreover, the concentration of IgA in the gallbladder is much higher than that in the blood, which has the function of protecting the intestinal mucosa from invasion (secondary bile acids, etc.). The gallbladder mucosa has the function of secreting IgA antibodies, and the gallbladder becomes the main source of supply of intestinal Ig and therefore the main organ with protective antibodies, which is important for the immune defense of the biliary system. Immuoglobulin (Ig) is present in normal human bile, and the role of this substance is: 1. Lack of Ig substances can cause defects in small intestinal defenses, infectious diarrhea, infectious ascites and sepsis of digestive tract origin. The main role of Ig in the bile is to remove antigens and protect the biliary mucosa. Morvay pointed out through animal experiments that secondary bile acids can directly increase the incidence of colon cancer in animals; why are they susceptible to colon cancer after cholecystectomy, according to Vernivk et al. Secondary bile acids can enhance mitosis of colonic mucosal cells and predispose to colonic carcinogenesis. Because the concentration of secondary bile acids in the proximal colon is higher and the absorption of secondary bile acids in the right hemicolectomy is greater than that in the left hemicolectomy, cancer after cholecystectomy is more likely to occur in the right hemicolectomy. The pathophysiological changes are: ① Origin of secondary bile acids: bile acids secreted from the hepatic bile ducts are primary bile acids, which are changed into secondary bile acids after entering the intestine in contact with bacteria. After cholecystectomy, the gallbladder loses its function and cannot control the excretion of bile and its residence time in the intestine; therefore, the primary bile acid flows into the intestine continuously for 24 hours and comes into contact with bacteria, producing a large amount of secondary bile acid, which undoubtedly increases the risk of colon carcinogenesis. In recent years, many European scholars have found a phenomenon and doubt that many cases of colon cancer have a history of gallbladder removal, and Moorehead analyzed 100 cases of biliary excision and 100 cases of non-biliary excision over 60 years of age and found that the number of those with colon cancer was 12:3 respectively, which was very surprising. However, when the gallbladder functions normally, bile is only discharged into the intestine when eating, and there is no more bile in the intestine during fasting, so obviously there are few opportunities for primary bile acids to come into contact with bacteria, and therefore the amount of secondary bile acids produced is very small, and coupled with the existence of normal gallbladder, there is a large amount of Ig in the bile to protect the intestinal mucosa from foreign antigens and secondary bile acids, which of course reduces the possibility of colon cancer. Therefore, the advice of Nordic doctors who study colon cancer to not remove the gallbladder casually is very reasonable.