Gall Bladder Functions and Problems

The gall bladder is a small sac located under the liver on the right side of the upper abdomen. The main function of the gall bladder is to store a liquid called bile, which is made by the liver. The gall bladder sends bile into the duodenum, the first part of the small intestine, when fat enters the intestine. Here the bile emulsifies the fat, breaking it into small droplets. Emulsification makes it easier for digestive enzymes in the duodenum to digest the fat. While bile is stored in the gall bladder, water is removed from it and the bile becomes concentrated, which in some people can lead to the formation of solid lumps known as gallstones.

The gall bladder is shaped like a pear and can hold about 50 mL of bile. When full, the gall bladder is about 8 cm (3.2 inches) long and 4 cm (1.6 inches) wide. The tube that transports bile out of the gall bladder is called the cystic duct. This joins with the hepatic duct which transports bile out of the liver to form the common bile duct. The common bile duct then joins with the pancreatic duct coming from the pancreas and sends the bile into the duodenum.

Bile can flow in either direction in the cystic duct – either into the gall bladder from the liver or out of the gall bladder towards the duodenum.

Bile is a watery solution that contains bile salts, cholesterol, fats, some protein and bilrubin. Bilirubin is a yellow pigment formed from the breakdown of hemoglobin from old or damaged red blood cells.

Two types of gallstones are produced from bile – cholesterol stones and pigment stones. About eighty percent of gallstones are made of solidified cholesterol and are known as cholesterol stones. Pigment stones are made of solidified bilrubin.

Cholesterol stones are yellow in color, but if they contain other substances as well as cholesterol they may be greenish yellow or brownish yellow. Pigment stones are black or dark brown. Black pigment stones form in the gall bladder. Brown pigment stones often form in the bile ducts and may be related to infections. The technical name for the presence of gallstones in the gall bladder is “cholelithiasis.” Gallstones may be tiny or as large as a golf ball.

Gallstone formation seems to be due to a combination of several factors. It’s thought that heredity plays a role. If the gall bladder has a decreased ability to contract and release its bile, the likelihood of gallstone formation increases. Other risk factors for developing gallstones include gender (woman are more susceptible than men), age (people over the age of sixty are more likely to develop gallstones than younger people), obesity and excess estrogen in the body (such as estrogen provided by birth control pills or hormone replacement therapy). Pregnant woman also have a high level of estrogen in their body and are susceptible to developing gallstones.

Bile salts in bile (or very similar compounds called bile acids) are responsible for emulsifying fats in the duodenum. However, they also break up some of the cholesterol in the bile. Therefore if the bile doesn’t contain enough bile salts, gallstones can form.

Certain ethnic groups seem to have a higher genetic tendency to develop gallstones. For example, gallstones are more common in people of Native America, South American or Northern European descent. People of Asian descent are more likely to develop pigment stones than cholesterol stones.

People with diabetes often have a high level of triglycerides in their blood and an increased risk of developing gallstones.

It’s important to maintain a healthy weight to reduce the chance of developing gallstones. Research has shown that even being moderately overweight increases gallstone risk. However, if you’re trying to lose weight, the excess weight should be lost gradually. During rapid weight loss the liver excretes extra cholesterol into the bile (which is one mechanism by which excess cholesterol is removed from the body), increasing the risk of gallstones. Some medications prescribed to lower blood cholesterol cause the same effect by stimulating secretion of cholesterol into bile, which can result in gallstone formation.

Interestingly, although weight gain must be avoided, regularly eating a small amount of a healthy fat, such as monounsaturated fat and omega-3 fat, helps prevent gallstones, because it stimulates the gall bladder to contract in order to release bile. The amount of saturated fat in the diet should be greatly reduced, however, since saturated fat increases the level of cholesterol in the body.

A high fiber diet reduces gallstone formation. Fiber - especially wheat bran - is known to lower the blood cholesterol level. Although scientists are not ready to make definite claims, several research studies have shown that regularly drinking caffeinated coffee can reduce the risk of gallstone formation. Some studies show that Vitamin C also decreases gallstone production. In addition, regular exercise helps prevent gallstones.

If gallstones move out of the gallbladder they can block any of the passageways in the biliary system, including the cystic duct, the hepatic duct and the common bile duct. Gallstones may also enter the pancreatic duct.

While gallstones are in the gall bladder there are often no symptoms, although there may be pain after eating a fatty meal if many gallstones are present or if they are large. However, if gallstones move into the tubes that conduct bile and block them, a person may experience the symptoms of a “gall bladder attack”, also known as biliary colic. These symptoms may include pain in the middle of the upper abdomen, in the upper right abdomen, under the right shoulder and between the shoulder blades. The pain may be severe. It starts shortly after eating and may last for several hours. There may also be nausea and vomiting. Gall bladder attacks may be recurrent.

In some people, blocked bile ducts or a blocked pancreatic duct can lead to complications such as inflammation of the gall bladder (cholecystitis) or pancreas (pancreatitis) and infections. Yellow skin and whites of the eyes (jaundice) may result when the bile ducts are obstructed by gallstones, causing bilirubin from the trapped bile to collect in the body. Although jaundice itself is not serious, it may have a serious underlying cause. Abdominal pain that does not go away or abdominal pain accompanied by fever, chills or jaundice requires immediate medical attention.

Gallstones that stay in the gallbladder and don’t cause any problems are known as “silent” gallstones. These are not treated. The body may be able to deal with small gallstones that leave the gall bladder by itself. These gallstones move with the bile into the duodenum. From here, the stones will travel through the rest of the small intestine, then into the large intestine and out of the body in the feces.

Larger gallstones or gallstones that block passageways are more problematic. There are non-surgical methods to treat gallstones but unfortunately they are not very effective, and if they do work gallstones often reappear in the future.

Ursodiol (also known as ursodeoxycholic acid) is a bile acid. It is prescribed to break up cholesterol gallstones. Ursodiol works best with small stones. However, it needs to be taken for months before it starts to work and may need to be taken for up to two years. For fifty percent of patients, gallstones reappear within five years of stopping the ursodiol treatment.

There are recipes on the Internet for gall bladder flushes, which usually include some combination of apples, apple juice, apple cider vinegar, lemon or grapefruit juice, magnesium (usually in the form of Epsom salts), and a large quantity of olive oil. Components of the apple juice are supposed to soften the stones and the olive oil is supposed to force the gall bladder to contract and push the softened gallstones into the intestine. Ingesting the gall bladder flush recipe often causes the appearance of solid lumps in the feces, but scientists have analyzed the lumps released from some people who have undergone a flush and have found that they aren’t gallstones but are derived from olive oil.

Extracorporeal shock wave lithotripsy (ESWL) is the use of high energy sound waves to break up gallstones. It works best with small, single stones. Lithotripsy is not used very much nowadays. It can cause serious side effects, such as broken fragments of gallstones from the gallbladder becoming trapped in bile ducts, and there is a high risk of gallstone recurrence.

There are other methods that doctors use to break up gallstones in situations when surgery is not advisable, but at the moment the most effective way of solving a gallstone problem is to remove the gall bladder. We don’t need a gall bladder to survive. Some bile normally flows directly from the liver through the hepatic duct towards the duodenum. If a person lacks a gall bladder, all the bile flows from the liver to the duodenum. Traditional surgery to remove the gall bladder is called a cholecystectomy. A more common method of removing the gall bladder is known as a laparoscopy, which is minimally invasive.

Scientists still have a lot to learn about the factors that cause and prevent gallstone formation. Hopefully in the near future they will understand gallstones better and will have improved treatment methods which don't require removal of the gall bladder.