Inflammation of the Liver and Bile Ducts
Inflammatory bowel disease (IBD), which encompasses Crohn's disease and ulcerative colitis, causes inflammation of the digestive tract. For up to 50% of people with IBD, the liver or gallbladder are also affected.1 Complications outside the intestine are called “extraintestinal manifestations” of IBD.
Functions of the liver
Your liver has many important functions. These functions include helping with digestion, storing nutrients, removing toxins, and fighting infections. To aid digestion, the liver makes bile. Bile is a fluid that helps you to digest fat.2 Bile is made up of water, bile salts, cholesterol, and a pigment called bilirubin, among other things. It breaks big fat drops into smaller droplets that are easier to absorb. Bile leaves the liver though bile ducts. It is stored in the gallbladder or it flows right into the small intestine.
Crohn's and UC in the liver and bile ducts
Manifestations of Crohn's and ulcerative colitis in the liver and bile ducts include primary sclerosing cholangitis, autoimmune hepatitis, and gallstones. These conditions are described below. IBD may also affect other liver conditions, such as fatty liver disease and viral hepatitis.
What is primary sclerosing cholangitis?
Primary sclerosing cholangitis (PSC) is a disease that damages bile ducts inside and outside the liver.3 Inflammation causes scars to form within the bile ducts. Eventually, the ducts become narrow due to the scarring. Bile can no longer flow freely out of the liver. It begins to build up in the liver and cause damage.
No one knows what causes PSC.4 However, it is closely linked with inflammatory bowel disease. This fact leads researchers to think it is caused by an abnormal immune reaction. About 5% of people with inflammatory bowel disease have PSC.5 Yet 75% of people with PSC have inflammatory bowel disease. PSC mainly affects people with ulcerative colitis. However, a small percentage of Crohn’s colitis have this complication as well.6 If you are diagnosed with PSC first, your health care provider may do tests to check for inflammatory bowel disease.1
Symptoms of PSC include fatigue, itching, jaundice, pain, bleeding within the digestive tract, abdominal swelling, and confusion.5 However, almost half of people with PSC do not have symptoms.4 The goal of treatment for PSC is to relieve symptoms. Some people have a procedure to open up the scars in the bile ducts. There are no treatments that cure or slow PSC.
What is autoimmune hepatitis?
Autoimmune hepatitis is a condition in which the body attacks its own liver cells.7 Although people with inflammatory bowel disease are at higher risk of autoimmune hepatitis, overlap with ulcerative colitis is more common than with Crohn’s disease.1 Autoimmune hepatitis and PSC often overlap in the same person.4 Autoimmune hepatitis is different from viral hepatitis, such as Hepatitis B and C.
Autoimmune hepatitis causes flu-like symptoms.7 These symptoms include fatigue, joint pain, nausea, and pain. Other symptoms include dark yellow urine, light-colored stools, and yellowing of the skin and eyes (jaundice). Medications used to treat autoimmune hepatitis include corticosteroids and immunosuppressants. Untreated autoimmune hepatitis can lead to scarring (cirrhosis) and liver failure. A liver transplant may be needed.
Do Crohn's and colitis cause gallstones?
In a study that compared people with Crohn’s disease and ulcerative colitis to the general population, people with Crohn’s disease had twice the risk of developing gallstones compared to people without inflammatory bowel disease. People with ulcerative colitis did not have an increased risk; however, people with ulcerative colitis can also develop gallstones.8 About 13% to 34% of people with Crohn’s disease have gallstones.9 If Crohn’s disease affects your ileum, your risk is particularly high.10
What are gallstones?
Gallstones are hard particles that form in the gallbladder.11 One reason they form is that bile salts are not properly reabsorbed. Usually, bile salts are reabsorbed at the end of the small intestine, called the ileum. However, the ileum is sometimes removed to treat Crohn’s disease. It may also be so inflamed that it does not work properly.
The bile salts travel into the large intestine, where they mix with bilirubin. The bilirubin transforms into a form that can be reabsorbed back into your body. It travels back to the liver and is added to the next “batch” of bile. The extra bilirubin in the bile causes black gallstones to form.10
Complications of gallstones
Gallstones may not cause any symptoms. In this case, no treatment is needed.12 However, gallstones that block ducts can cause complications.11 The common bile duct is the “main road” for bile. Three other ducts lead into the common bile duct:
- Cystic duct, which starts at the gallbladder.
- Hepatic duct, which starts at the liver.
- Pancreatic duct, which starts at the pancreas.
If a gallstone blocks the cystic duct, it can cause increased pressure in the gallbladder.11 If the gallbladder is blocked for more than a few hours, it may become inflamed, swollen, and damaged. A gallstone can also block the shared outlet for bile and pancreatic juices. When this happens, the pancreas may become inflamed. Untreated blockages can be fatal.