The gallbladder along with the bile ducts form the biliary system. The biliary system or biliary tree involves organs or ducts involved in storage or transportation of bile in the body. Bile is a greenish colored fluid produced in the liver which helps in digestion. The liver is also sometimes included in this biliary system due to a network of small bile ducts which are present in the liver.

SEQUENCE OF BILE TRANSPORTATION
Bile is produced in the liver and through a network of small bile ducts it flows into the right and left hepatic ducts. These ducts drain into the common hepatic duct (CHD), which joins the cystic duct from the gallbladder to form the common bile duct (CBD). Bile then flows down into the first part of the small intestine called the duodenum.
Not all bile flows into the bile duct but around half of it is stored in the gallbladder. The gall bladder is a pear-shaped organ located just below the liver. When we eat food the gallbladder contracts and releases bile into the duodenum to help digest fats.

FUNCTIONS OF THE BILIARY SYSTEM
Bile released from the bile ducts into the duodenum helps in digestion of fats as well as fat soluble vitamins like vitamin D and A.
Bile also helps to eliminate waste from the liver and passing it onto the intestine.
The role of bile in elimination of waste is evidenced by the dark brown color of stool which is due to breakdown of bile.

DISEASES OF THE BILIARY SYSTEM
1. Gall bladder stones is one of the commonest diseases to affect the biliary system. It can lead to an infection in the gallbladder called cholecystitis.
2. Biliary obstruction – this can occur if gallstones pass into the bile duct and block the flow of bile into the duodenum. This can lead to severe pain, fever and jaundice.
3. Infection of the biliary tree – biliary cholangitis or sclerosing cholangitis
4. Painless enlargement of the bile ducts – choledochal cyst
4. Cancer of the gall bladder
5. Cancer of the bile ducts

SYMPTOMS OF DISEASES OF BILIARY TRACTS
Symptoms of biliary disease vary from the type of disease to the location of the disease.
Diseases like choledochal cysts can have no symptoms.
Most common symptoms of infection within the biliary tree include pain, nausea or vomiting, jaundice, fever, hyperacidity, etc.
Symptoms of cancer can include symptoms similar to infection with the addition of weight loss, fatigue, tiredness in some.

DIAGNOSING BILIARY DISEASES
1. Routine blood tests like complete blood count, liver function test, help in evaluating the biliary system
2. Radiology tests like ultrasound is one of the best tests to identify gall bladder stones.
3. CT scan may sometimes be needed to evaluate and evidence of gallbladder abscess, infection, etc.
4. MRI with MRCP is the test of choice to evaluate the entire biliary tree. It provides a detailed visualization of all the bile ducts.
5. EUS in addition helps to give additional information and to take a biopsy in some cases.

TREATMENT
1. Medical management to help regularize flow in the biliary system as well as antibiotics to take care of the infection.
2. Endoscopy including ERCP to treat obstruction within biliary tree.
3. Drainage of biliary tree incase of infections
4. Surgery which included Laparoscopic cholecystectomy for gall bladder stones, excision of bile duct with drainage of biliary system in cases with choledochal cyst or bile dut cancer, etc.