What to do about gallstones
The gallstone story begins with the liver's production of bile, a substance used by the small intestine to digest fatty foods and aid in the absorption of certain vitamins. Bile is made in a network of tiny ducts in the liver and carried by a larger duct to the gallbladder, a small, pear-shaped organ that concentrates and stores it. When we eat, the fat in food triggers the release of a hormone that causes the gallbladder to contract and release bile into the intestine.
Problems arise when the stored bile crystallizes and forms solid lumps, or gallstones. Their size can range from as small as a grain of sand to as large as a golf ball. About 80% of gallstones are made primarily from cholesterol. The other 20% — known as pigment stones — are made of calcium salts and a substance called bilirubin, which is a breakdown product of red blood cells.
Cholesterol stones form when the liquid bile becomes supersaturated, containing more cholesterol than bile salts can dissolve. They may also develop if the gallbladder doesn't contract and empty as it should. Pigment stones are associated with certain medical conditions, including liver disease, some types of anemia, and infection of the bile ducts.
Women are at a much higher risk for developing gallstone disease than men, because the female hormone estrogen increases cholesterol in the bile. As we age, the development of gallstones slows somewhat in women and increases in men. Under age 40, women are diagnosed with gallstones almost three times more often — pregnancies, for example, increase the risk — but by age 60, they have only a slightly higher incidence. The drop-off in estrogen at menopause may be one reason. Estrogen therapy increases the risk, although the patch form of the hormone appears to cause fewer problems than oral estrogen.
Obesity, especially in women, is another risk factor for gallstones, because fat tissue influences the amount of estrogen produced in the body. Rapid weight loss also increases risk; very low–calorie diets interfere with bile production, causing more crystallization of cholesterol. Gallstones are so common after weight-loss surgery that patients are often advised to have their gallbladders removed at the time of surgery. Finally, gallstones are more likely to occur in people with diabetes, high triglycerides, or any condition that decreases gallbladder contractions and intestinal motility, such as a spinal cord injury.
Gallstone symptoms arise only when stones pass through a bile duct or obstruct it, causing biliary colic — more commonly known as a gallbladder attack. An attack begins with pain, usually in the right upper or middle abdomen, that builds to its greatest intensity within an hour and persists for up to several hours. Pain sometimes radiates to the back or the right shoulder. It may be either sharp and knife-like or a deep ache.
If you think you're having a gallbladder attack, your clinician will probably order several blood tests and an abdominal ultrasound exam to check for stones. Other techniques used to diagnose gallbladder disease include cholescintigraphy, a radioactive injection used to view a possible blockage of the cystic duct; magnetic resonance imaging of the bile ducts; and endoscopic retrograde cholangiopancreatography, which uses a scope to view the biliary ducts. An advantage of this last technique is that stones can sometimes be removed during the procedure.
Gallstones should be treated only if they cause symptoms. For recurrent gallbladder attacks, the most effective treatment is surgical removal of the gallbladder, or cholecystectomy. The traditional procedure is a major surgery requiring a five-inch incision and a hospital stay of up to a week. Fortunately, it has been largely replaced by laparoscopic cholecystectomy, in which the surgeon removes the gallbladder with instruments inserted through small incisions in the skin, below the liver. This procedure requires only an overnight hospital stay and a week of recovery at home.
There is a slight risk of injuring the bile ducts during laparoscopic cholecystectomy. Also, in 5%–10% of cases, the surgeon may have to switch to an open surgery because of complications such as bleeding or old scarring.
There are few downsides to living without a gallbladder. When it is removed, bile simply flows directly into the small intestine through the common bile duct. Bile in the intestine when no food is present may cause loose stools, but that problem can be treated with a bile acid–binding medication.
If you are unable or unwilling to undergo surgery and your gallstones are relatively small, one nonsurgical option is to take ursodiol, a naturally occurring bile acid that helps dissolve cholesterol. Ursodiol can take up to two years to work and will dissolve only those gallstones made of cholesterol. Other medications are under investigation.
Drug therapy is occasionally combined with lithotripsy, which uses sound waves from outside the body to break gallstones into pieces that dissolve more easily or are small enough to safely pass through the bile duct. Unfortunately, stones are likely to recur after medical treatment.
There's no proven way to prevent gallstones, but several studies have linked moderate alcohol consumption to a lower risk of symptom-causing gallstones. The Nurses' Health Study also found that women who ate several one-ounce servings per week of peanuts or other nuts were less likely to require gallbladder surgery, as were women who ate more fiber. Gallbladder surgery was also less common in regular exercisers.
April 2005 Update