According to most estimates, about 20-25 million Americans suffer from gallstones each year in the United States. While most cases aren’t severe and even asymptomatic, there are still many people who require treatment, including surgery to remove the gallbladder. Yet as relatively common as gallbladder disease is, it is only one of a variety of medical conditions that can affect the biliary system, a network of organs and ducts that play an important role in digestion and the absorption of fats.

What Is the Biliary Tract?

The biliary tract (also sometimes referred to as the biliary tree) is a set of biological structures that includes the liver, gallbladder, and bile ducts. The primary purpose of the biliary system is the production, storage, and transportation of bile, a fluid composed of water, bile salts, and bilirubin. Bile is introduced to the gastrointestinal tract via the duodenum, the first part of the small intestine, and it has several functions in the digestive process:

  • Emulsification of fats: Bile also contains bile acids, a set of substances made from cholesterol that act as emulsifiers. Emulsification is the process of breaking down large fat globules into smaller droplets; this increases the surface area available for digestion by lipase, an enzyme produced by the pancreas. This process makes it easier for lipase to break down fats into fatty acids and glycerol, which can then be absorbed by the small intestine.
  • Absorption of fats: Because of the way bile acids emulsify fat, bile in general helps facilitate the absorption of fats as well as fat-soluble vitamins (A, D, E, and K) and cholesterol in the small intestine. After fats are broken down into smaller droplets by bile, they can be more effectively absorbed through the intestinal lining into the bloodstream.
  • Stomach acid neutralization: Another component of bile is bicarbonate ions, which help neutralize the acidic contents of the stomach as they enter the small intestine. This neutralization creates a more favorable environment for the action of pancreatic enzymes and protects the lining of the small intestine from damage by stomach acid.
  • Waste product elimination: Bile also serves as a route for the elimination of waste products from the body like bilirubin (a product of the breakdown of hemoglobin) and excess cholesterol. These waste products are excreted in bile and eventually eliminated from the body through the feces.

Functionally, the production of bile starts in the liver through a type of cell called a hepatocyte; as this fluid is secreted by the liver, it accumulates and collects in the common hepatic duct. This duct then joins the gallbladder’s cystic duct to form the common bile duct, which drains into the duodenum via the ampulla of Vater. About half the bile we need comes directly from the liver, and the other half is stored in the gallbladder. Every time we eat, the gallbladder contracts and releases bile into the digestive tract.

Possible Disorders of the Biliary Tract

Bile is a crucial part of the digestive system because of how it helps break down food and aids the absorption of nutrients in the small intestine. There are a number of conditions that can negatively affect the production of bile or generally lead to dysfunction of the biliary system. Below are some of the most common disorders and diseases:

  • Gallstone disease: Also known as cholelithiasis, gallstone disease is a condition that involves the formation of hardened deposits of bile components. Gallstones typically form when the bile contains too much of any component (usually cholesterol or bilirubin). In most cases, these hardened deposits resolve on their own, but they can also cause a variety of symptoms like abdominal pain in the right upper quadrant (biliary colic), nausea, vomiting, or a yellowing of the skin and eyes (jaundice). If left untreated, gallstone disease can lead to pancreatitis or other complications.
  • Gallbladder inflammation: Inflammation of the gallbladder (acute cholecystitis) is another common biliary problem that is most often caused by gallstones blocking the cystic duct. The symptoms are similar to gallstone disease and also include abdominal pain, nausea, and fever. Without prompt treatment, inflammation of the gallbladder can lead to a rupture of the gallbladder or an infection.
  • Biliary obstruction: While an obstruction in the cystic duct can lead to gallbladder inflammation, a nearby bile duct obstruction can lead to inflammation as well as a variety of other problems like nutritional deficiencies, liver scarring (biliary cirrhosis), or chronic liver disease.
  • Primary biliary cholangitis (PBC): PBC is an autoimmune condition characterized by inflammation and destruction of the bile ducts within the liver. Over time, progressive damage to the bile ducts can lead to liver scarring and impaired liver function. Symptoms of PBC include fatigue, itching, abdominal discomfort, and jaundice.
  • Primary sclerosing cholangitis (PSC): PSC is a chronic inflammatory disease that is similar to PBC; the primary difference between the two is that PBC mainly affects smaller bile ducts while PSC mainly affects larger ones. PSC can cause narrowing and obstruction by bile duct stones. The impact of PSC on the digestive tract can also have an impact on incidence of inflammatory bowel disease.
  • Biliary dyskinesia: Biliary dyskinesia refers to abnormalities in the emptying of the gallbladder that stem from dysfunction of the sphincter of Oddi, a muscular “valve” that regulates the flow of bile.
  • Cholestasis: This condition involves impairment of the flow of bile that can occur due to gallstones or another disease. It is mainly caused by a buildup of bile salts in the liver.

    Diagnosis of Biliary Tract Diseases

    Most problems with the biliary tract aren’t identified until after symptoms begin to manifest, and even then it can take time to determine the likeliest cause (particularly since the symptoms for these different diseases can be so similar). To diagnose a problem with the biliary system, the gastroenterologist will usually start with a review of the patient’s medical history and a physical examination. Blood tests may also be used to assess liver function and to look for telltale markers of a biliary disease.

    Additionally, imaging tests like an endoscopic ultrasound or CT scan can help the doctor visualize the biliary tract. One test that is especially suited to viewing the biliary system is magnetic resonance cholangiopancreatography (MRCP), a type of high-resolution scan that doesn’t require a contrast agent. Another option is endoscopic retrograde cholangiopancreatography (ERCP), a specialized procedure that combines endoscopy and fluoroscopy to detect biliary stones, strictures, or tumors. In some situations, a laparoscopic biopsy may be used to get a tissue sample from the liver that can confirm the diagnosis or assess the amount of liver damage.

    Treatment Options

    The treatment options for most biliary tract disorders will be based on the underlying condition and the severity of symptoms. Below are some common approaches to treatment:

    • Watchful waiting: Most gallstones are asymptomatic, so the first step is often an examination followed by a period of observation over weeks or months. Dietary changes, such as reducing fat intake, may also help alleviate symptoms.
    • Medication: Apart from pain killers and other drugs used to ease symptoms, there are medications that can dissolve gallstones or improve liver function.
    • Surgery: In more serious cases, or cases where other treatments don’t work, surgery may be necessary. The go-to surgery for symptomatic gallstones is removal of the gallbladder (cholecystectomy). If the bile ducts have become too narrow, biliary dilatation can essentially stretch them out. For PBC, PSC, and other severe problems, a liver transplant is one of the final options.

    Request an Appointment with Cary Gastroenterology

    Gallstones and other problems with the biliary tract are relatively common, but they are fortunately conditions that have a high likelihood of being successfully treated. If you have been experiencing any symptoms like those discussed above, it’s best to get evaluated by a healthcare provider. At Cary Gastro, our dedicated and professional team is eager to help you get the treatment you need. Please contact us to request an appointment.