Gallstones are collections of crystals that grow and solidify into "stones" in the gallbladder. Most gallstones are predominantly crystals of cholesterol alone or with some calcium (80-90%). Gallstones can also be composed of crystals containing calcium and bilirubin. Bilirubin is a by-product of red blood cell breakdown and recycling.
What is going on in the body?
The gallbladder stores bile, a yellowish-green liquid made in the liver. Certain fatty drugs and hormones are excreted from the body in bile. Bile also aids in digestion. When a person eats, bile flows through a series of tubes or ducts into the upper part of the small intestine (the duodenum). It helps to "break up" food, especially fats and vitamins that are dissolved in fat so that they can be absorbed into the body. When bile is supersaturated, that is, when it contains more cholesterol or bilirubin than it can hold in solution, crystals may precipitate that eventually grow into gallstones.
What are the causes and risks of the condition?
Gallstones are crystals that form from excess cholesterol or bilirubin in the gall bladder. Factors that increase a person's risk for gallstones include:
- diet high in calories, low in fiber, high in "refined" carbohydrates, or low in unsaturated fats
- excessive breakdown of red blood cells, such as sickle cell anemia (for bilirubin stones)
- race (Native American, especially Pima Americans, and Mexican American)
- pregnancy and parity (that is many pregnancies)
- increasing age
- a family history of gall-stone disease
- female gender
- decreased physical activity
- birth control pills and other estrogen replacement
- prolonged fasting or rapid weight loss
- metabolic states like type 2 diabetes mellitus that have a resistance to insulin
What can be done to prevent the condition?
Many cases cannot be prevented. However, maintaining a normal weight with regular excercise may reduce a person's risk, especially of the largest and most painful stones.
How is the condition diagnosed?
Diagnosis of gallstones starts with a medical history and physical exam. Blood tests may be included (for instance, an elevated bilirubin and liver enzymes may suggest that a gall stone has blocked bile excretion from the liver). An ultrasound may be ordered to check for gallstones.
If a gallstone has left the gall bladder and blocked bile excretion, a CT scan (CAT scan) or an MRI (Magnetic Resonance Imaging) may be used to visualize it. A specialized test called an ERCP can diagnose and remove a gall stone that may also block the duct leading from the pancreas. This is performed by a specialist using a scope passed through the duodenum into the bile ducts to visualize them directly.
Long Term Effects
What are the long-term effects of the condition?
Many people have asymptomatic gallstones for years without problems (80%). However, complications of gallstones may include:
- blockage of the ducts that carry bile to the intestines
- bowel obstruction
- infection of the liver ducts
- liver disease
- pancreatitis, or inflammation of the pancreas when a gall stone blocks its duct
- in select instances a higher incidence of gall bladder cancer
What are the risks to others?
Gallstones are not contagious and pose no risk to others.
What are the treatments for the condition?
Asymptomatic gallstones are not treated except in children, obese people who are going to undergo aggressive treatment such as weight loss surgery, and in those individuals who are at higher risk for gallbladder cancer (those with larger stones, so-called "porcelain gallbladder" and Native Americans). These individuals are recommended for surgical removal of the gall bladder before the onset of symptoms, because they are at higher risk for complications from gallstones.
Once gallstones start to cause symptoms, most persons should have the gall bladder removed. In uncomplicated cases, the surgeon can remove the gall bladder through a small incision using a laparoscope. This approach shortens the recovery time, reduces the pain, and often eliminates the need for a hospital stay. If gallstone disease is complicated by obstruction of the ducts or infection, the more traditional surgical approach through a full incision may be required. If the person is acutely ill with an infected gall bladder, the surgery may have to be done as an emergency.
Treatments other than surgery are used in some cases but are much less effective. Some medicines, such as ursodiol, can dissolve very small (<5mm) gallstones if they contain no calcium. Few people qualify for this approach. A procedure using special sound waves similar to that used for breaking up kidney stones (lithotripsy) was tried for gallstones but has now been abandoned completely.
What are the side effects of the treatments?
Infrequently, surgery may be complicated by bleeding, infection, and reactions to the anesthetic. Some people may notice more frequent bowel movements for a short time after surgery.
What happens after treatment for the condition?
Gallstones recur after they are dissolved with medicines. Most people have no further problems following gall bladder surgery.
How is the condition monitored?
Any symptoms of significant abdominal pain should be reported to a healthcare provider.