To understand what the gall bladder is, it is important to understand some basics about the digestive system.
Food goes from the mouth to the stomach through the oesophagus. If moves from the stomach to the small bowel then the large bowel where undigested food is excreted from the anus.
The small bowel is divided into three parts: the duodenum, jejunum and ileum.
When food moves from the stomach into the duodenum, it mixes with bile and pancreatic juices which break down the food further so that it can be absorbed into the blood stream through the wall of the small intestine.
The pancreas secretes its enzymes into the duodenum through its pancreatic duct – a channel which links the pancreas to the duodenum.
Bile is a substance made by the liver and is important for the digestion of fat. It enters the duodenum through a channel which connects the liver to the duodenum called the bile duct.
Some of the bile is stored into the gall bladder (which comes off the side of the bile duct).
When a fatty meal is ingested, the gall bladder contracts to deliver some ready-made bile from the gall bladder into the duodenum.
If the gall bladder is removed surgically, bile still travels normally from the liver into the duodenum through the bile duct.
Bile is made of a mixture of constituents which are finely balanced. When this balance changes, gravel starts to form within the bile which eventually forms stones.
There are many genetic and environmental causes for this balance to change and thus for stones to form.
Once stones are formed, they do not dissolve.
Stones can cause no symptoms but may temporarily block the gall bladder causing pain called biliary colic. They may block the gall bladder and cause inflammation of the gall bladder called cholecystitis. Smaller stones may escape from the gall bladder and travel down the bile duct blocking it causing cholangitis or block the pancreatic duct causing pancreatitis.
Asymptomatic gall stones do not usually require surgery. (except when the patient is diabetic, immunosuppressed or where there are multiple tiny stones which increase the risk of acute pancreatitis).
Symptomatic gall stones should be treated by removing the gall bladder (cholecystectomy).
Gall stones cannot be removed without removing the gall bladder.
Unlike kidney stones, gall stones cannot be treated with lithotripsy as this would just result in smaller stones escaping from the gall bladder and causing a bigger problem blocking the bile duct or the pancreatic duct.