Gallstone disease is a common medical problem affecting 10 to 15% of the population of the United States. About 1 million new cases of gallstone disease are diagnosed every year in this country. Half of these require treatment.
Gallbladder Function
The gallbladder is a sac on the underside of the liver. It is connected to the liver and the intestine by a series of small tubes, or ducts. The primary job of the gallbladder is to store bile until the bile is needed to aid in digestion. After a meal, the gallbladder contracts and sends the bile into the intestine. When digestion of the meal is over, the gallbladder relaxes and once again begins to store bile.
Gallstone Formation
Gallstones are pieces of hard solid matter in the gallbladder. They form when the components of bile (especially cholesterol and bilirubin) precipitate out of solution and form crystals, much as sugar may collect in the bottom of a syrup jar. In general, either cholesterol or bilirubin precipitates out of solution to form stones, but not both. In the United States, 75% to 80% of patients with gallstones have cholesterol stones. Gallstones may be as small as a grain of sand or as large as a golf ball, and the gallbladder may contain anywhere from one stone to hundreds. Sometimes the gallbladder contains only crystals and stones too small to see with the naked eye. This condition is called biliary sludge.
No one knows why some people develop gallstones and others don't, but doctors do know some things which seem to increase the risk of developing stones. Anything which increases the amount of cholesterol in bile increases the risk of cholesterol stones, and things which increase the bilirubin in bile increase the risk of pigment (bilirubin) stones. Other factors are probably also important in gallstone development, such as poor contraction of the gallbladder muscle with incomplete emptying of the gallbladder, and the presence of substances in bile which may speed up or delay precipitation of crystals. Many people with gallstones have a combination of factors. Exactly how diet affects gallstone formation is not clear, but diets which are high in cholesterol and fat and low in fiber may increase the risk of developing gallstones.
Who Is At Risk?
- Patients with severe liver disease.
- Patients with some blood disorders such as sickle cell anemia.
- Women over 20, especially pregnant women.
- Men over 60 years old.
- Overweight men and women.
- People on 'crash diets' who lose a lot of weight quickly.
- Patients who use certain medications, including birth control pills and cholesterol-lowering agents.
- Native Americans and Mexican Americans.
Symptoms
- Upper abdominal or right-sided pain after meals.
- Pain may also be felt between the shoulder blades or in the right shoulder.
- Nausea or vomiting.
- Fever.
- Jaundice.
It is thought that gallstone pain results from blockage of the gallbladder duct (cystic duct) by a stone. When the blockage is prolonged (greater than several hours), the gallbladder may become inflamed. This condition, called acute cholecystitis, may lead to fever, prolonged pain and eventually infection of the gallbladder. Hospitalization is usually necessary for observation, treatment with antibiotics and pain medications, and frequently for surgery.
More serious conditions may occur when a gallstone passes out of the gallbladder duct and into the main bile duct. If the stone lodges in the main bile duct, it can lead to a serious bile duct infection. If it passes down the bile duct, it can cause an inflammation of the pancreas, which has a common drainage channel with the bile duct. Either of these situations can be extremely dangerous. Stones in the bile duct usually cause pain, fever, and jaundice (yellow discoloration of the eyes and skin).
Many people with gallstones have no symptoms. Often the gallstones are found when a test is performed to evaluate some other problem. So-called 'silent gallstones' are likely to remain silent, and no treatment is recommended.
Diagnostic Evaluation
When symptoms are consistent with biliary disease, a series of tests may be performed, from simple lab work to sophisticated invasive tests:
- Liver function tests.
- Abdominal Ultrasound.
- Nuclear Medicine imaging (HIDA Scan).
- MRCP (Magnetic Resonance Cholangiopancreatography).
Treatment
Many new approaches to gallstone treatment have been tried over the past several years, but surgical removal of the gallbladder (cholecystectomy) remains the most widely used therapy.
Alternatives to invasive procedures
Gallbladder stones can be dissolved by a chemical, which is available in pill form. This medicine thins the bile and allows stones to dissolve. Unfortunately, only small stones composed of cholesterol dissolve rapidly and completely, and its use is therefore limited to patients with the right size and type of stones.
A problem with all non-surgical approaches is that gallstones return several years later in about half the patients successfully treated.
Note: The materials presented in this section are for general information and do not substitute for medical advice. Patients have the right to receive accurate, easily understood information about their health plans, professionals, and facilities, and to a choice of health care providers sufficient to ensure access to appropriate high-quality health care.