The Facts

Gallstones are crystal-like masses that typically form in the gallbladder. The gallbladder is a small organ located on the right side of the abdomen, just below the liver. The gallbladder's main function is to store bile (made by the liver) and secrete it into the small intestine to help with digestion. Bile is made of water, cholesterol, fats, bile salts (natural detergents that break up fat), and a pigment called bilirubin. Gallstones form if the bile contains too much cholesterol, bile salts, or bilirubin.

There are 2 types of gallstones. Cholesterol stones contain mostly hardened cholesterol and account for approximately 80% of gallstones. Pigment stones are made of bilirubin and account for the other 20%. Gallstones can range in size from very small to as large as a golf ball. The gallbladder may develop any number and size of stones.

Gallstones are more common in women and people who are older, as well as in certain groups of people, such as Indigenous populations and people who are overweight. In Canada, 20% of women and 10% of men over the age of 60 have gallstones, but many never experience symptoms. However, complications from gallstones can be serious if symptomatic stones are left untreated.


Medical understanding of how gallstones develop is increasing. It's believed that gallstones may be caused by a combination of factors including heredity, obesity, and the ability of the gallbladder to contract (motility).

Cholesterol gallstones form when there's too much cholesterol in the bile and not enough bile salts. Problems with the gallbladder's motility may cause the bile to become too concentrated and lead to stone formation.

The cause of pigment stones is uncertain. They tend to develop in people with pre-existing conditions such as cirrhosis, biliary tract infections, and hereditary blood disorders such as sickle cell anemia. They may also be caused by infections.

Risk factors that may lead to the formation of gallstones include:

  • gender – women between 20 and 60 years of age are 3 times as likely to develop gallstones as men
  • age – people over the age of 40
  • estrogen – people who are pregnant or using hormone replacement therapy (HRT)
  • obesity – a large clinical study showed that being even moderately overweight increases the risk for gallstone formation
  • ethnicity – some ethnic groups, including Indigenous populations, have a higher prevalence of gallstones
  • diabetes – people with diabetes have an increased the risk of gallstones
  • rapid weight loss – this causes the liver to secrete extra cholesterol into the bile
  • fasting – this inhibits the gallbladder's ability to contract, causing high concentrations of cholesterol to build up in the bile
  • a diet high in fat and sugar along with an inactive lifestyle – this sets the stage for increased risk for gallstones
  • medications – certain medications, such as octreotide and ceftriaxone, have been linked to the formation of gallstones

Symptoms and Complications

80% of people with gallstones don't have symptoms. Gallstones in these cases are known as silent stones. They're sometimes detected during tests for an unrelated condition and usually don't need to be treated.

Problems arise when a gallstone attack occurs. Attacks may occur over a period of weeks, months or even years. However, once a full attack occurs, subsequent attacks are more likely. One attack may last from 20 minutes to several hours. Symptoms of an attack include:

  • persistent, severe pain in the upper middle or upper right abdomen that increases rapidly
  • pain in the back between the shoulder blades
  • pain under the right shoulder
  • sweating, nausea and vomiting

Other signs and symptoms of gallstones may be vague and non-specific.

The gallbladder is attached to the liver and small intestine by a series of tubes called ducts. Complications can occur if gallstones block the flow of bile by lodging in any of the ducts that carry the bile from the liver and gallbladder to the small intestine. Trapped gallstones may lead to gallbladder inflammation (cholecystitis) and infection of the bile ducts (cholangitis). Gallstones may also become trapped in the pancreatic duct, which can cause painful inflammation (pancreatitis).

Beware of symptoms such as jaundice (yellowing of the skin and whites of the eyes), fever, clay-coloured stools, tea- or coffee-coloured urine, and persistent pain.

Making the Diagnosis

When symptoms seem to indicate a gallstone, your doctor may suggest an ultrasound of the abdomen. A technician will pass a handheld device that emits sound waves over the abdomen. Sound waves bounce off organs and other solid masses, revealing the presence of gallstones.

In addition, blood test results may show a pattern of abnormal liver enzymes that suggests bile ducts may be obstructed by gallstones. Several other tests can provide additional information needed to make a firm diagnosis.

Treatment and Prevention

Some of the risk factors for gallstone formation can be modified, such as obesity. By maintaining a healthy weight through proper diet and exercise, a person can reduce the chances for gallstones. Also, one should avoid diets that result in losing weight very quickly as risk of developing gallstones will increase.

Most people who have "silent" gallstones in the gallbladder don't require treatment. People with intermittent pain can try avoiding or reducing their intake of fatty foods.

If someone has gallstones in the gallbladder that cause repeated attacks of pain, the doctor may recommend removing the gallbladder. This type of surgery is called a cholecystectomy.

People who have gallstones may develop problems when the gallbladder becomes inflamed. This is called acute cholecystitis. In these cases, sufferers are hospitalized so they can receive fluids intravenously, and antibiotics are usually given as soon as the problem is suspected. If the diagnosis is certain and surgery is not considered risky, the gallbladder is usually removed during the first day or two of the illness.

Today, almost all cholecystectomies in Canada are performed using laparascopic surgery under general anaesthesia. The surgeon makes small incisions in the abdomen and inserts surgical instruments as well as a video camera that projects a magnified view of a patient's internal organs onto a monitor. The gallbladder is removed through one of the incisions. Most people are able to go home after the surgery, but some people may require an overnight stay for additional monitoring.

Open cholecystectomies may be performed if complications are discovered, such as infection or scarring from previous operations. A surgeon may start using laparascopic techniques then switch to open surgery if such a complication is found. In very obese individuals, an open cholecystectomy may be easier to perform.

A person can live normally without a gallbladder. Once removed, bile flows from the liver through the ducts and directly into the small intestine. No change in diet is necessary, although the more frequent flow of bile to the small intestine may lead to diarrhea.

For people who are not able to have surgery, a medication called ursodiol can be used to help dissolve some types of gallstones. This medication takes about 6 months to work and is effective in only about 50% of people who use it. Gallstones usually come back once a person stops taking the medication.

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