What is it?
A gallstone is a hardened deposit of digestive fluid in the gallbladder. The gallbladder is a small, pear-shaped organ beneath your liver, and is part of the biliary tract. The biliary tract includes the gallbladder, which stores bile made by the liver, and the bile ducts, which carry the bile and digestive enzymes between the liver, pancreas, and small intestine. Most gallstones (80%) are formed from gallbladder, although 20% are darker, smaller pigment stones made up of bilirubin.
What causes Gallstones?
Gallstones form when there is an imbalance in the substances that form bile, including cholesterol, bilirubin, and bile salts. They may also form if the gallbladder doesn’t empty frequently or entirely. In those cases, the bile becomes very concentrated and forms into hard stone particles.
Normal bile has enough chemicals to dissolve the cholesterol excreted by the liver, but if the liver excretes more cholesterol than the bile can dissolve, it forms into crystals and eventually gallstones. Pigment stones are caused by an excess of bilirubin, which is produced when the body breaks down red blood cells. Pigment gallstones are more common in people with cirrhosis or blood disorders.
Who is at risk?
There are several risk factors for gallstones. Extra estrogen can increase cholesterol in bile and decrease gallbladder contractions, so gallstones are more likely to form. Women, especially those who are pregnant, take birth control pills, or are undergoing hormone replacement therapy, are at higher risk of developing gallstones. Obesity also increases the amount of cholesterol in bile. During rapid weight loss, the breakdown of fat causes the liver to secrete extra cholesterol. The gallbladder may not empty properly during rapid weight loss, which also increases the risk of gallstones.
As with most digestive disorders, diet plays a major role in the development of gallstones. A high-fat diet, a high-calorie diet, a high-cholesterol diet, and a low-fiber diet all increase the risk of gallstones. Native Americans and Mexican Americans are prone to gallstones, as are diabetics and the elderly.
Risk Factors for Gallstones:
- Rapid weight loss
- Older age
- Poor diet
- Some cholesterol-lowering medications
- Intestinal diseases
- Family history of gallstones
Signs and Symptoms
Many gallstones are asymptomatic, and do not interfere with the function of the gallbladder, liver, or pancreas. A patient may learn that he or she has gallstones only while undergoing an examination for a different illness. In some cases, gallstones can block the bile duct and cause a gallbladder attack. Symptoms include nausea, vomiting, bloating, indigestion, gas, heartburn, and pain the upper abdomen and back.
Gallbladder attacks usually follow heavy meals, and last for a few hours. If a bile duct remains blocked for more than a few hours, the gallbladder can become inflamed or infected. If it is located near the pancreas, it can cause pancreatitis. If you experience abdominal pain lasting more than five hours, nausea and vomiting, fever and chills, or jaundice, call a doctor immediately.
The first step in diagnosis is usually a blood test. This can rule out other potential conditions, and reveal any complications that could be caused by gallstones, such as infection, jaundice, and pancreatitis.
The next step is often imaging. Ultrasounds are the most accurate method for detecting gallstones, although doctors may recommend a CT scan to look for infections and blockages, or an MRI to detect gallstones in bile ducts.
During a HIDA scan, safe radioactive materials are injected into the body. A camera follows the material as it moves through the biliary system. This scan, also called cholescintigraphy, can diagnose bile duct obstructions and abnormal gallbladder contractions.
An endoscopic retrograde cholangiopancreatography (ERCP) allows the doctor to look for and remove gallstones. An endoscope is inserted through the mouth, and a contrast medium is injected so the ducts appear on the monitor. The stone can then be scooped out in a tiny basket attached to the endoscope. This is a more invasive test, and is used selectively.
If gallstones aren’t causing symptoms, treatment is generally unnecessary. However, gallbladder attacks can be serious, and generally recur. Gallbladder removal, or cholecystectomy, will relieve gallstones. The American Medical Association and the American College of Surgeons list cholecystectomy as one of the most common surgeries in the United States. A laparoscopic cholecystectomy is used about 80% of the time. This surgery is less invasive and has fewer complications than an open cholecystectomy.
There are a a few nonsurgical treatments for cholesterol gallstones, but these are only used when there is some reason a patient can’t undergo surgery. Gallstones can frequently recur within five years after nonsurgical treatments.
Oral dissolution therapy involves medication (Actigall or Chenix) that contain bile acids to dissolve small cholesterol stones. It can take several months or even years for all gallstones to be dissolved via this method. Shock wave lithotripsy may be used along with Actigall. In this treatment, a lithotripter generates shock waves that break the gallstone into smaller pieces.
Doctors will often recommend dietary changes in addition to surgical or nonsurgical treatment. A proper diet is essential to an optimal digestive system.