Gallstone disease is the most common disorder affecting the biliary system, the body's system of transporting bile. Gallstones are solid, pebble-like masses that form in the gallbladder or the biliary tract (the ducts leading from the liver to the small intestine). They form when the bile hardens and are caused by an excess of cholesterol, bile salts or bilirubin.
Types of Gallstones
There are two types of gallstones:
- Cholesterol stones: These are yellow-green stones, predominately found in women and obese people. Cholesterol stones account for 80 percent of gallstones. This is the most common type in the United States.
- Pigment stones: These may be black or brown and tend to develop in patients who have other liver conditions, such as cirrhosis or biliary tract infections.
Gallstone Disease Symptoms
Many people with gallstones do not experience any symptoms. Often, symptoms only appear when there are complications. The complications may be caused by inflammation, infection or obstruction.
The main symptom of gallstone disease is biliary colic. Biliary colic appears suddenly and builds quickly to a peak. It is a constant abdominal pain, usually in the right upper side of the abdomen, lasting anywhere from 15 minutes to several hours. This pain is usually aggravated by meals, especially fatty food.
Biliary colic may also include:
- Fatty food intolerance
- Right shoulder pain
- Yellowing of the skin or eyes
- Clay-colored stool
Gallstone Disease Diagnosis
A diagnosis of gallstone disease begins with a comprehensive physical exam during which you describe your symptoms and medical history. Often, the physical exam will be completely normal. Sometimes, your doctor can feel the gallbladder, and there may be some abdominal tenderness. Other diagnostic procedures include:
- Laboratory tests
- Imaging scans
- Endoscopic diagnosis
Blood tests will check your liver function. If there are complications from gallstones, the tests will be abnormal.
Gallstones, especially those that are asymptomatic, are often discovered accidentally during an imaging scan for another problem. If you need an imaging scan based on your history and physical exam, there are a number of procedures available. Imaging scans use different technologies to determine the presence and location of gallstones.
- Ultrasound: An abdominal ultrasound is the best noninvasive test for detecting gallstones in the gallbladder. An ultrasound uses sound waves to create images of your organs. It is a simple, safe and painless procedure that provides accurate information about the presence of gallstones.
- CT scan: A CT scan is a powerful X-ray. It can detect complications of gallstone disease, such as excess fluid, gas in the gallbladder wall, gallbladder perforations and abscesses (collections of pus in the body). A CT scan may help determine if you need urgent surgical intervention.
- MRI and magnetic resonance cholangiopancreatography (MRCP): An MRI uses strong magnetic waves to create a detailed picture. An MRCP uses MRI imaging with special software to help detect gallstones and bile duct stones and evaluate the gallbladder for presence of cholecystitis (inflammation).
- Cholecystingraphy: You receive an intravenous radioactive substance, which your liver absorbs and then is secreted into the gallbladder and bile ducts. Scans are then taken that can accurately detect acute inflammation of the gallbladder.
An endoscope is a thin, flexible, lighted tube inserted into your mouth. It reaches your esophagus, stomach and small intestine. Using the endoscope, you doctor can visualize your biliary system.
Endoscopic Retrograde Cholangiopancreatography
Endoscopic retrograde cholangiopancreatography (ERCP) is the preferred method for detecting gallstones in the common bile duct. Because the endoscope is in position, stones can be removed during an ERCP. During this procedure:
- A special side-viewing endoscope called a duodenoscope is used.
- This scope is specially designed to allow the placement of necessary accessories into the bile and pancreatic duct and remove bile duct stones.
- A catheter is used to inject dye into the ducts.
- An X-ray is taken to obtain images of your pancreatic and biliary ducts.
Endoscopic ultrasound (EUS) uses both an endoscopy and an ultrasound to evaluate and diagnose digestive tract disorders, and together they produce detailed images of your bile duct and gallbladder. Unlike an ERCP, an EUS cannot be used to remove gallstones. However, it is an accurate diagnostic tool and presents a lower risk of complications than ERCP.