“My stomach hurts, my back hurts, I can’t eat, and I’m very fatigued,” said a myPBCteam member. For some people with primary biliary cholangitis (PBC), digestive issues like diarrhea, nausea, and stomach cramps can add even more stress. If you’re feeling sick to your stomach with PBC, you’re not alone.

PBC can affect digestion by destroying the bile ducts. This means less bile reaches the intestines, where it’s needed to break down fat. Without enough bile, the body may have trouble digesting fat, which can cause diarrhea or stomach pain. People with PBC may also have gastrointestinal (GI) issues for other reasons, like another health condition or a food intolerance.

“My internal stomach ‘workings’ are just crazy,” wrote another member. “I had no real stomach problems before diagnosis and being put on meds. The occasional heartburn was all. Now, I have gas pains, heartburn, bloating, and gallbladder attacks. Even my stomach seems to be getting bigger.”

Here are six reasons why diarrhea, nausea, and stomach cramps are such common complaints for people with PBC.

1. Fat Malabsorption

Normally, bile acids flow into the small intestine, helping the body break down dietary fat and absorb fat-soluble vitamins. However, this process doesn’t work as it should for people with PBC. Less bile gets released to the gut, making it harder to digest fat. Undigested fat can cause diarrhea and stomach issues.

Some vitamins, like A, D, E, and K, need fat to be absorbed. If your body isn’t absorbing fat well, it may not absorb these vitamins either. Your doctor can check for signs of vitamin deficiencies and may suggest supplements or other treatments to help your body get the nutrients it needs.

2. Bacterial Overgrowth

There are trillions of microorganisms living in our intestines. These bacteria and other species work together to help our bodies digest food, make vitamins, and support the immune system.

Lower bile acid levels in PBC allow an overgrowth of some forms of bacteria. This disrupts the healthy balance and can lead to digestive problems like bloating, gas, constipation, diarrhea, and stomach pain.

Your doctor can test for bacterial overgrowth with a breath test. To support healthy bacteria, try eating a variety of plant foods, fermented foods, and yogurt. Probiotics are helpful bacteria that you can get from food or supplements. Also, try to avoid using antibiotics unless necessary because they can disrupt your body’s natural bacterial balance.

3. Other Gastrointestinal Conditions

People with PBC are more likely to develop digestive disorders like celiac disease. Celiac disease is an autoimmune disease where the body reacts negatively to gluten, a protein found in wheat, barley, and rye. Eating even small amounts of gluten triggers an immune response that damages the intestines. Diarrhea, nausea, and stomach pain are all common symptoms of celiac disease.

Studies also suggest a relationship between inflammatory bowel disease (IBD) and PBC. Crohn’s disease and ulcerative colitis are two common types of IBD. People with IBD have a wide range of digestive symptoms, including diarrhea and stomach cramps.

Crohn’s disease is more strongly linked to PBC than ulcerative colitis. Although researchers aren’t exactly sure why there’s a connection, it may have to do with shared genetic risks or the influence of inflammation on the GI tract. So far, there’s evidence that Crohn’s raises the risk of PBC, but not the other way around. However, it’s possible to get diagnosed with PBC without knowing that you already have Crohn’s disease.

People with PBC can also have hypothyroidism, which means their thyroid levels are low. This condition can lead to constipation and stomach pain.

Ask your healthcare provider if you think you might have a digestive disease aside from PBC. They can recommend the right tests and specialists to help you figure out what’s going on.

4. Food Triggers

Even if you don’t have a specific digestive disorder, some foods may not agree with you. Many people have problems digesting certain foods, which can lead to stomach cramps, nausea, and diarrhea. Common food intolerances include:

• Lactose — In dairy products
• Gluten — In products that contain wheat, barley, and rye
• Histamine — In foods like avocados, bananas, chocolate, cheese, and pineapples

Keeping a food diary, where you write down what you eat and what symptoms you have, can help you spot patterns. If you think you have a food sensitivity, talk to a registered dietitian. They can help you pinpoint the problem and show you how to read food labels to avoid certain ingredients.

5. Medication Side Effects

Some medications used to treat PBC can cause digestive problems. Ursodiol (also called ursodeoxycholic acid and sold under the brand name Urso) is the most common treatment for PBC. It’s a long-term treatment that can help people with PBC live longer. However, many members of myPBCteam say they have digestive issues when taking it. “I get diarrhea and stomach cramps shortly after eating and taking ursodiol. Does anyone else have this issue?” asked a myPBCteam member. Another member agreed: “Yes, ever since I started it. No matter what I eat.”

Some members found strategies to manage these side effects. “We switched to taking it at night, which helped. It rarely happens to me unless I eat high-fat food,” one member said. Another wrote, “For me, it was worse when I started the Urso. The doctor and I agreed to lower the dose. I take it twice daily at a reduced dosage, which seems to have helped a lot. The doctor says as long as my numbers stay down, he’s OK with it.”

Despite its benefits, ursodeoxycholic acid doesn’t usually help with pruritus (itchy skin), one of the biggest issues for people with PBC. To ease itchiness, doctors usually prescribe cholestyramine, a type of medicine called a bile-acid sequestrant. It works by trapping bile acids in the intestines (also called the gut) so they don’t build up and cause itching. Unfortunately, one of its main side effects is GI problems.

It’s important to share any potential side effects and concerns with your healthcare providers. Finding the right PBC treatment plan for you can take some time and trial and error. If you’re having a lot of side effects, they may suggest changing your dose or adjusting your medication. However, don’t change your medications without talking to your doctor first.

6. Advanced Liver Disease

PBC can also cause severe liver damage, leading to nausea and vomiting. When it causes cirrhosis (advanced scar tissue on the liver), people may lose their appetite, lose weight without trying, and develop fluid buildup in the abdomen (ascites), making it feel swollen or firm. They’re also at higher risk for abdominal infections and liver cancer, which can cause GI symptoms. Another telltale sign of liver failure is yellowing of the skin and whites of the eyes, called jaundice.

Although drinking alcohol doesn’t cause PBC, it can make liver damage worse. Avoiding alcohol and living a healthy lifestyle can help preserve your liver function and general health. If liver disease progresses too far, a liver transplant can help. Discussing this treatment option with your doctor in advance can help you feel prepared if the time comes to have a transplant.

Talk With Others Who Understand

On myPBCteam, the social network for people with primary biliary cholangitis and their loved ones, members come together to ask questions, give advice, and share their stories with others who understand life with primary biliary cholangitis.

Have you had digestive symptoms of PBC, ursodiol nausea, or complications of liver disease? Share your experiences in the comments below, or start a conversation by posting on your Activities page.