The digestive juice known as the bile is produced by the liver and stored in the gallbladder. When food is consumed, the bile is released into the small intestines through the bile ducts. The bile is responsible for the breakdown of food materials and is made up of substances such as cholesterol, bile acids, bilirubin and salts. There are various diseases that can affect the bile ducts resulting in blockage causing similar symptoms. Some of the causes of blockage to the bile ducts include gallstones, injury to the bile ducts during a surgery, cancer, primary sclerosing cholangitis and birth defects such as biliary atresia.
Gallstones
Gallstones are small stones that block the duct within the gallbladder. This can cause intensive abdominal pain that can last for up to five hours. The cause of gallstones is associated with the imbalance of the bile material within the gallbladder such as excess cholesterol.
Bile duct cancer
Depending on the location of cancer in the bile duct system, it is divided into three types. The intrahepatic bile duct cancer develops in the small bile ducts located inside the liver. Perihilar bile duct cancer occurs where the right and left hepatic ducts are merged and are exiting the liver. The distal bile duct cancer occurs in the ducts closer to the small intestine.
Primary sclerosing cholangitis
This condition is caused by an inflammation resulting in scars of the bile ducts. Over time, this may progress slowly making the ducts hard and narrow causing serious liver damage. The exact cause of this condition is not known, however, the immune system’s response to an infection can trigger the onset particularly in individuals who are genetically predisposed to it.
Biliary atresia
This is a life-threatening condition where the bile ducts within or outside the liver do not have proper openings. This results in the bile accumulation and causes damage to the liver. This is not an inherited condition and develops in the womb as the result of infections, genetic mutation, immune system problem or error with the development of bile ducts.
Symptoms
The blocked bile duct may develop symptoms abruptly or may progress slowly over several years until the bile duct inflammation has occurred. Some of the symptoms associated with blocked bile duct include; jaundice, light brown urine, itching, weight loss, fever, fatigue, greasy stool, abdominal pain and loss of appetite.
Diagnosis
A blood test can measure the levels of alkaline phosphates and bilirubin. Some of the tests used to diagnose bile duct problems include right upper quadrant ultrasound, CT or MRI scan of the liver and x-rays of the bile duct (cholangiography) where dye is injected to observe the bile flow from the liver. In some cases, a liver biopsy may be required to determine the presence of inflammation or cancer.
Treatment
The gallstone blockage can be removed using a process known as endoscopic retrograde cholangiopancreatography. The early diagnosis is beneficial in treating the bile duct cancer with surgery which may involve the rerouting of the bile duct. The radiation therapy can reduce the size of a tumor but cannot cure it completely. When infants are affected with the biliary atresia, a surgery may reroute the bile duct or substitute the missing section of the bile duct. The primary sclerosing cholangitis can result in liver failure requiring liver transplantation. Medications can treat the itching caused by bile duct conditions and a low-fat diet may be beneficial for greasy stool.
References
http://www.cancer.org/cancer/bileductcancer/detailedguide/bile-duct-cancer-what-is-bile-duct-cancer
https://medlineplus.gov/bileductdiseases.html
http://www.nhs.uk/Conditions/Gallstones/Pages/Introduction.aspx
http://www.health.harvard.edu/diseases-and-conditions/bile-duct-diseases
