What are gallstones?
Gallstones or Cholelithiasis are hard stone-like deposits made of cholesterol or bilirubin that can develop in the gallbladder or bile ducts. They are solid masses formed from bile precipitates. They can cause pain.
They can vary in size from a grain of sand to a golf ball. Therefore, you may have one large gallstone, hundreds of tiny stones, or both small and large stones.
Gallstones are very common. About 15% of the adult population suffers from gallstones and most of them do not have any symptoms. Such asymptomatic cases are left alone.
However, 10% of the people who are diagnosed with gallstones develop symptoms within 5 years. Such symptomatic people usually require surgery to remove their gallbladder.
Surprisingly, it is the small stones that usually cause symptoms. Most commonly, multiple small gallstones about 0.5 cm in diameter will be present within the gallbladder. Since they cause symptoms, they require surgery.
Being small, they move out of the gallbladder and get stuck in the bile duct. The larger stones remain in the gallbladder and do not cause trouble.
It is when the gallstones move from the gall bladder into the bile duct and block it that you get the pain of gallstones.
About the gallbladder and bile
The gallbladder is a small, pear-shaped organ situated in the right hypochondriac region of the abdomen, just beneath the liver. It is about 3 inches long and 1 inch wide at its thickest part.
Its main function is to store the digestive enzyme called bile that is made by the liver and release it into your small intestine when you start eating. The gallbladder is green in color due to the bile present in it.
Bile comprises mainly cholesterol, bilirubin, bile salts, and lecithin.
From the gallbladder, the bile enters the bile duct, which empties the bile into the duodenum, the first part of the small intestine.
Bile is released directly into the small intestine either through the hepatic duct that comes straight from the liver or from the bile ducts that comes from the gallbladder. The cystic duct connects the gallbladder’s neck to the common hepatic duct, which drains into the common bile duct and then into the duodenum.
After having performed its function of digesting the fats in your food, the bile is excreted through the feces.
This entire network of ducts and the associated organs such as the liver, gallbladder, and pancreas make up the biliary system or the biliary tract.
The main function of the bile is to help in the digestion of the fats in the food that you eat. Before you start eating, your gallbladder is filled with bile.
When your food contains very little fats, the gallbladder empties poorly, but when significant quantities of fat are present in the food that you eat, the gallbladder empties completely
When you start eating, the gall bladder is prompted by hormones and the vagus nerve to release bile into your duodenum through the bile duct.
When food is being digested in the stomach and later in the first part of the small intestine (duodenum), the gallbladder begins to empty, especially when fatty foods reach the duodenum about 30 minutes after you have eaten a meal.
Bile acts as an emulsifier and breaks down the large fat globules into smaller droplets. It helps to break down fats, absorb vitamins, and remove wastes. After you have eaten, your gallbladder is empty and deflated.
Types of gallstones and what are they made of?
There are two types of gallstones: cholesterol and pigment stones.
- Cholesterol stones account for 80% of gallstones. They are yellowish-green and are mainly made of cholesterol. You will find them mostly in obese people, and more so in women. In this type of gallstone, the bile is supersaturated with cholesterol. These gallstones are mainly responsible for obstruction and inflammation.
- Pigment stones are black or brown in color.
- Black pigment stones are made of calcium bilirubinate or compounds of calcium, copper, and mucin glycoproteins. These gallstones typically form when there is stoppage or slowdown in bile flow or when there is an elevated level of unconjugated bilirubin caused by hemolysis or liver disease such as cirrhosis. Black pigment stones usually stay put in the gallbladder and do not go out into the bile duct.
- Brown pigment stones are made of calcium salts of unconjugated bilirubin and 20–80% cholesterol and protein. These stones are often located in bile ducts and cause occlusion of their lumen leading to bile flow obstruction. Further fallout is the development of an infection in the ducts called cholangitis. Brown pigment stones are common in Asian countries but are rarely seen in the United States.