The gallbladder is a small organ located underneath the liver. Its primary function is to store bile, which helps with digestion. Gallstones develop within the gallbladder and bile ducts from the buildup of hard particles of bilirubin or cholesterol.
Gallstones can range from being microscopic to the size of a golf ball. Some people affected by gallstones may only have one or two, whereas others may have hundreds of stones within their gallbladder.
In the United States alone, up to 25 million people are affected by gallstones, with nearly 10-15 percent of Americans developing gallstones at some point in their lives.
However, up to 80 percent of people will not display any symptoms of the condition. Doctors usually discover these silent gallstones when they are looking for other sources of concern on an abdominal ultrasound or other imaging procedure.
Experts suspect that up to 20 percent of people with gallstones in their gallbladder will also have them in their bile duct system.
Gallstones: Causes and types
When gallstones get stuck in the bile ducts, it causes choledocholithiasis.
Gallstones may vary in cause and type. Traditionally, gallstones are divided into three main types.
These stones are typically brown pigment stones that form within the bile ducts, such as the common bile duct.
Pigment gallstones are made from a substance found in the body called bilirubin.
These yellow-green stones form within the gallbladder and are usually made of cholesterol.
Cholesterol gallstones are typically found in one of the bile ducts after they have traveled from the gallbladder. These are the most common type of gallstones found in developed countries.
These gallstones are a combination of two or more substances, including calcium, phosphate, protein, and cystine
Recent research has uncovered eight types of gallstones with 10 subtypes.
Residual and recurrent gallstones
Sometimes, stones may be left behind after the removal of the gallbladder (cholecystectomy). Typically, they are found within 3 years after a person has undergone the procedure.
Recurrent gallstones continue to develop within the bile ducts after the gallbladder has been removed.
There are several risk factors for developing gallstones. These risk factors include the following:
A diet high in calories with little fiber may increase the risk of developing gallstones. Obesity is also a risk factor.
- being female and having elevated levels of estrogen
- taking hormone replacement therapy or birth control
- being over 40 years old
- having a family history of gallstones
- being of Native American or Mexican-American descent
- rapid weight loss
- diets high in calories and refined carbohydrates and low in fiber
- having a history of gastrointestinal conditions, such as Crohn's disease
- having metabolic syndrome, diabetes, or insulin resistance
- having cirrhosis or infections of the bile duct system
- having hemolytic anemia, such as sickle cell disease
In addition to having gallstones as a risk factor for choledocholithiasis, people are also at risk if they have had their gallbladder removed or if they have had a previous history of gallstones in the bile ducts.
Those with existing risk factors or concern about developing gallstones should speak with their doctor to work out their risk for both gallstone formation and choledocholithiasis.
When a gallstone causes a person pain, it is because the stone is blocking the liver, gall bladder, or bile ducts. At times, this can lead to severe discomfort. Some people with gallstones do not experience any symptoms, however.
People may experience gallbladder disease as pressure or pain in the upper right abdomen, most commonly after eating a heavy meal. Pain is typically located behind the breastbone and can also move to the shoulder blades.
When a stone blocks a bile duct, symptoms may include:
- pain, which can be severe lasting for several hours
- yellowing of the skin and whites of the eyes
- nausea and vomiting
- light-colored stool
- dark, tea-colored urine
There are complications of gallstones and blocked ducts, some of which may be fatal. These complications include:
- gallbladder or liver inflammation
- damage to the gallbladder, bile ducts, or liver
- bacterial infection
- gallstone pancreatitis, an inflammation of the pancreas
Due to the severity of these complications, it is important for people with choledocholithiasis to get treatment as soon as possible.
During evaluation for gallstones, doctors may use several diagnostic tools to test for gallstones and other conditions with similar symptoms.
Some other conditions that have similar symptoms to gallstones include:
- gallbladder cancer
- gallbladder inflammation or infection without stones
- acid reflux
- biliary dyskinesia, the improper movement of bile through the bile duct system
Doctors may recommend using certain radiologic tools during the evaluation and diagnosis process. Some of these tests may include:
- computerized tomography (CT) scan
- magnetic resonance imaging (MRI)
Cholescintigraphy also called a hydroxyl iminodiacetic acid scan (HIDA scan), is a type of nuclear medicine scan used to evaluate the gallbladder and biliary system.
Another radiologic test that could be used is endoscopic retrograde cholangiopancreatography (ERCP). This is a test that uses a lighted tube with a camera on the end to examine the bile and pancreatic ducts. Dye is injected into these ducts and X-rays are taken.
Doctors may recommend testing substances within the blood to better evaluate the liver. This may be referred to as liver function testing and includes checking levels of the following substances:
- alkaline phosphatase
- ALT and AST enzymes
- gamma glutamyltransferase (GGT)
Additionally, certain other blood tests may be carried out to check for infection or other concerns.
The results of these tests will provide doctors with helpful information on how the body is working. For example, they will be better able to determine if there is infection present or if the liver is inflamed.
Once a doctor has made a diagnosis of choledocholithiasis, they will likely recommend certain procedures or surgery to remove the stone or stones blocking the bile duct. The most common procedure for this is called an ERCP with sphincterotomy.
An endoscopy may be performed before surgery, to help the surgeons accurately locate and remove the gallstone.
During this procedure, the surgeon uses a lighted tube with a camera on the end, called an endoscope, to view the ducts of the liver and pancreas.
They then make a small incision called a sphincterotomy to remove the stone from the bile duct. This duct empties into the small intestine.
For those who have developed an infection of the bile ducts called cholangitis, ERCP is typically recommended to remove the stones. Removing any blockages and giving antibiotics are the most important steps in the treatment of this condition.
The most effective treatment for active gallbladder disease continues to be the removal of the gallbladder. The procedure usually takes place once the stones have been removed and any inflammation or infection has improved.
Shock wave lithotripsy, a procedure that crushes the gallstone into smaller pieces with shock waves, is also an option but rarely used due to the high risk of stone reoccurrence.
This procedure may be offered to individuals who have common bile duct stones that cannot be removed with ERCP. It may also be useful for dissolving a single stone within the gallbladder.
A downside to this procedure tends to be that an endoscope procedure is often needed afterward to remove the stone debris.
Medications have not been shown by research to be an effective treatment for active gallbladder disease.
Anyone who has occasional signs or symptoms of gallstones should speak with their doctor. If their symptoms are persistent or severe, they should visit their local emergency room for more urgent evaluation and treatment.
Anyone with choledocholithiasis needs prompt medical attention to limit complications.