Gallstones

Overview

Gallstones are pieces of solid material that form in the gallbladder. They may be as small as a grain of sand or as large as a golf ball. The gallbladder may develop a single often large stone or many smaller ones. Gallstones occur in up to 20 per cent of Canadian women and 10 per cent of men by the age of 60.

Causes

Gallstones form when liquid stored in the gallbladder hardens into pieces of stone-like material. There are two types; cholesterol stones and pigment stones. Scientists believe cholesterol stones form when bile contains too much cholesterol too much bilirubin or not enough bile salts or when the gallbladder does not empty as it should for some other reason. They account for about 90 percent of gallstones. The cause of pigment stones is less certain. They tend to develop in people who have cirrhosis biliary tract infections and hereditary blood disorders such as sickle cell anemia in which too much bilirubin is formed.

Other risk factors include:

Obesity. Obesity is a major risk factor for gallstones especially in women. A large clinical study showed that being even moderately overweight increases the risk for developing gallstones. The most likely reason is that obesity tends to reduce the amount of bile salts in bile resulting in more cholesterol. Obesity also decreases gallbladder emptying.

Estrogen. Excess estrogen from pregnancy hormone replacement therapy or birth control pills appears to increase cholesterol levels in bile and decrease gallbladder movement both of which can lead to gallstones.

Ethnicity. The indigenous population has a genetic predisposition to high levels of cholesterol in bile. In Canada 70-80 per cent of the native population is affected with this disease.

Gender. Women between the ages of 20 and 60 are three times more likely to develop gallstones than men and women who have had multiple pregnancies are also more likely to develop gallstones.

Age. People over age 60 are more likely to develop gallstones than younger people.

Cholesterol-lowering drugs. Drugs that lower cholesterol levels in blood actually increase the amount of cholesterol secreted in bile. This in turn can increase the risk of gallstones.

Diabetes. People with diabetes generally have high levels of fatty acids called triglycerides. These fatty acids increase the risk of gallstones.

Rapid weight loss. As the body metabolizes fat during rapid weight loss it causes the liver to secrete extra cholesterol into bile which can cause gallstones.

Fasting. Fasting decreases gallbladder movement causing the bile to become overconcentrated with cholesterol which can lead to gallstones.

Symptoms

Many people with gallstones have no symptoms. These patients are said to be asymptomatic and these stones are called "silent stones." They do not interfere with gallbladder liver or pancreas function and do not need treatment. In others people will experience gallstone attacks which can cause:

  • steady pain in the upper abdomen that increases rapidly and lasts from 30 minutes to several hours
  • pain in the back between the shoulder blades
  • pain under the right shoulder
  • nausea or vomiting

Gallstone attacks often follow fatty meals and they may occur during the night. Other gallstone symptoms include

  • abdominal bloating
  • recurring intolerance of fatty foods
  • colic
  • belching
  • gas
  • indigestion

People who also have the above and any of following symptoms should see a doctor right away:

  • chills
  • low-grade fever
  • yellowish color of the skin or whites of the eyes
  • clay-colored stools

Gallstone symptoms are similar to those of heart attack appendicitis ulcers irritable bowel syndrome hiatal hernia pancreatitis and hepatitis so accurate diagnosis is important.

Treatment

The Canadian Association of Gastroentology lists the following treatment options for gallstones:

Open Cholecystectomy

Open cholecystectomy is the classical surgical treatment for gallstones. Under general anaesthesia the patient's gall bladder is removed through an abdominal incision. The patient is required to remain in the hospital for five to seven days for recovery.

Laparoscopic Cholecystectomy

This medical procedure was introduced in 1990. Surgeons remove the gall bladder through small abdominal incisions using a lighted tube (called a laparoscope). The surgeon views the entire procedure on a television monitor. The procedure is done under general anaesthesia but because there is no cutting through the muscle of the abdominal wall the recuperation period is shorter.

Extracorporeal Biliary Lithotripsy

In this procedure doctors find the gallstones using an ultrasound machine and position the patient so the high-energy shock waves focus on the stones. The waves break the gallstones into fragments which either pass into the intestine or are dissolved with the help of medication. This treatment is performed in an outpatient setting however very few centres are available for this technique.

Other Treatment Methods

Oral Dissolution of gallstones by means of a medication ursodeoxycholic acid (ursodiol) involves no surgery and is therefore suitable for patients who are at high risk surgically. The best candidates are those with very small cholesterol gallstones and those who have mild symptoms.

Contact Dissolution requires medication to be administered into the gall bladder through a catheter. This therapy is appropriate for high-risk patients but must be carried out in very specialized units.

Prevention

Because obesity is a risk factor people should aim to maintain an ideal body weight. Otherwise there is no specific diet for gallstone disease. Very obese people who are attempting drastic weight reduction are at risk for developing gallstones. They should lose weight under medical supervision.

Additional Resources

Canadian Liver Foundation

The Canadian Association of Gastroentology