Bile Duct

What is a bile duct?

Bile ducts are tiny canals that connect some of the organs in your digestive system. Their purpose is to carry bile between these organs. The organs and bile ducts together form your biliary system. It includes your liver, your gallbladder and your small intestine.

What are bile ducts for?

Your body uses bile for several purposes. It needs bile ducts to carry bile safely from one place to the next. Bile needs to be able to move when and where your body needs it to, without interfering with other body processes or damaging other body parts.

Bile is a fluid your liver makes. It contains bile acids that help break down fats and proteins during digestion. These acids are damaging to organs that aren’t designed to carry them. Your bile ducts also carry digestive enzymes from your pancreas that have the same effect.

How do bile ducts connect the organs in my biliary system?

Your biliary system begins in your liver, in the upper right quadrant of your abdomen. Tiny branching bile ducts inside your liver collect bile as your liver makes it. These are called your intrahepatic (inside liver) bile ducts.

The intrahepatic ducts join together to form larger branches called the right and left hepatic ducts. These two branches join outside of your liver to form the common hepatic duct. (Branches outside of your liver are called extrahepatic ducts.)

Your common hepatic duct connects to your gallbladder through the cystic duct, forming the common bile duct. About half of the bile from your liver flows directly into the common bile duct, the main trunk of the biliary tree. The other half goes to your gallbladder.

Your gallbladder lies just underneath your liver. It’s a storage compartment for bile that isn’t needed right away. Your gallbladder receives bile from the common hepatic duct and holds it until it gets the signal that your small intestine needs it.

When your small intestine detects that it has fats and proteins to digest, it calls for resources. Your gallbladder squeezes bile out into the cystic duct. The cystic duct delivers it to the common bile duct, which will carry it down to your small intestine.

Your common bile duct is your biggest bile duct, about 10 centimeters (cm) long. This is where all the other bile duct branches connect. Your pancreatic duct joins the common bile duct at the same opening in your small intestine while remaining separate.

What conditions and disorders can affect my bile ducts?

Inflammation

Infections and other inflammatory conditions can cause bile duct issues, both in the short term and in the long term. In the short term, swelling from acute inflammation may narrow the passageways, stalling the flow of bile through your bile ducts.

In the long term, chronic inflammation in your bile ducts can eventually cause scarring of the tissues inside the ducts. Scar tissue inside your bile ducts will cause the passageways to narrow (stricture) and eventually to lose blood supply, which destroys your bile ducts.

Inflammation in your bile ducts is called cholangitis. Infections and blockages can cause acute cholangitis. Autoimmune diseases can cause chronic cholangitis. Primary biliary cholangitis and primary sclerosing cholangitis are two examples.

Obstruction

Obstructions are the most common cause of bile duct problems. The most common obstructions are gallstones. Gallstones are concentrated crystals of bile sediment that can form in your gallbladder or in your bile ducts. They grow gradually over many years.

Most commonly, gallstones form in your gallbladder and move out from there into your common bile duct. This specific condition has its own name: choledocholithiasis. If gallstones in your bile ducts grow large enough, they can obstruct the flow of bile.

Bile duct stricture can also obstruct the flow of bile. That’s when your bile ducts become narrow. Long-term inflammation can cause biliary stricture by creating scar tissue in your bile ducts. Birth disorders — such as biliary atresia and Alagille syndrome — can, too.

Cancer

Bile duct cancer (cholangiocarcinoma) can affect your extrahepatic bile ducts (most common) or your intrahepatic ducts, inside your liver. This is separate from liver cancer, which can also harm your intrahepatic ducts by compressing them or causing inflammation.

What will happen if your bile duct is blocked?

If bile can’t flow through your bile ducts, it’ll start to back up into your organs. This can cause inflammation and damage to your organs, including your gallbladder (cholecystitis), pancreas (gallstone pancreatitis) and your liver, as well as your bile ducts.

Stalled bile flow (cholestasis) also encourages infections to take hold. Infections in your biliary system can be acutely painful and dangerous. If they spread to your liver, they can enter your bloodstream and become systemic (septicemia). This can cause sepsis.

Backed-up bile can begin to leak into your bloodstream, causing various forms of illness. You may develop jaundice (a yellow tint to your skin and eyes), nausea, skin itching and even mild cognitive impairment (called hepatic encephalopathy).

Blocked bile ducts also can’t deliver bile to your small intestine when it’s needed. This can cause digestive problems. Your digestive system may have trouble breaking down fats and absorbing fat-soluble vitamins. Malabsorption can lead to malnutrition.

How do you know if you have bile duct problems?

Chronic conditions develop slowly over many years. You might not have symptoms until your bile ducts are already significantly damaged or destroyed. But if you have an acute condition, such as a blockage or infection, you’ll likely have symptoms of biliary colic.

Biliary colic is a type of abdominal pain, often accompanied by nausea and sometimes vomiting. It usually occurs after a fatty meal. It begins gradually and then steadily increases in intensity for up to an hour, then fades again over the next hour or two.

Biliary colic occurs when your biliary system is trying to deliver the bile to your small intestine to help with digestion. Your gallbladder contracts, which increases pressure in your bile ducts. If your bile ducts are infected or blocked, that pressure will be painful.

Go to the hospital right away if you have symptoms of biliary colic, even if they aren’t yet severe. Medical testing can quickly locate the problem. If you don’t have acute pain but have other biliary symptoms, such as jaundice, you may have a chronic disease.

How do you unblock your bile duct?

Healthcare providers have several procedures they can use to locate and remove blockages in your bile ducts. The type of procedure they recommend for you may depend on your condition, whether it’s chronic or acute and how urgent it is.

Endoscopic retrograde cholangiopancreatography (ERCP) is a non-surgical procedure that’s done by passing a long tube with a camera attached (endoscope) down your throat and into your GI (gastrointestinal) tract. Your doctor can operate through the endoscope.

A bile duct exploration is a surgical procedure. It can usually be done by minimally invasive methods, through one or several small cuts (incisions) in your abdomen (laparoscopic surgery). Sometimes it’s done during gallbladder removal surgery for gallstones.

Your doctor may remove a blockage by cutting into your bile duct or by propping it open with a stent. Sometimes they do both. If you have significant bile duct dilation due to scarring and stenosis, they might remove those sections of your ducts.

How can I take care of my bile ducts?

The biggest risk to your bile ducts is gallstones. A major cause of gallstones is high blood cholesterol. Extra cholesterol in your blood ends up in your bile and can solidify into cholesterol stones. You can reduce this risk by reducing cholesterol in your diet.

The second biggest risk to your bile ducts is liver disease. If you have chronic liver disease, you can help reduce cumulative damage to your liver and biliary system with healthy lifestyle choices. Exercise, reducing dietary fats and avoiding alcohol and drugs can help.

A note from Cleveland Clinic

Your bile ducts are tiny, but they play an important role in your body. Several organs and body processes depend on your bile ducts to do their daily jobs. When bile can’t flow where it needs to, eventually it leaks into your bloodstream, where it can affect your whole body.

Bile duct disorders can affect the organs in your biliary system, and disorders in those organs can affect your bile ducts, too. If you have biliary symptoms, such as biliary colic or jaundice, seek care right away to protect your fragile biliary system, including your bile ducts.