Does Cholestyramine Work for IBS Symptoms?

Nearly 15% of adults in the U.S. have symptoms of irritable bowel syndrome (IBS). This means that if you’re struggling with painful, irregular bowel movements, you are not alone. IBS can be a frustrating condition because experts still don’t know what causes it. Fortunately, there are a growing number of IBS treatment options. 

Let’s take a look at how cholestyramine can treat IBS symptoms. 

Does cholestyramine powder work for IBS?

Yes, cholestyramine powder can help improve symptoms of IBS in some people. 

Cholestyramine is a bile acid sequestrant, which means it binds to bile acids in the intestine. Bile acids are made in the liver, stored in the gallbladder, and released into the intestine after a meal to help digest fat. High levels of bile acid can lead to diarrhea by increasing mucous production and causing the intestine to push stool through the gut faster. By binding to bile acids, cholestyramine reduces the amount of free bile acids in the gut. This in turn can lessen diarrhea. 

There is evidence that some people with IBS have elevated bile acid levels in their stool. And using cholestyramine to lower bile acid levels can improve IBS-related diarrhea. 

It’s important to point out that cholestyramine isn’t FDA approved to treat IBS. But experts may recommend off-label use of cholestyramine to treat some people with IBS. 

When is cholestyramine recommended for IBS?

Cholestyramine isn’t right for everyone with IBS.

It may be helpful for people with diarrhea-predominant IBS (IBS-D) who haven’t gotten relief with other medications, like loperamide. People with IBS-D have bowel movements that are loose or watery at least 25% of the time.

Some studies suggest that more than half of people with IBS-D may have trouble absorbing bile acids. Cholestyramine can help reduce diarrhea in these cases. Your healthcare team may recommend blood and stool tests to see if you have trouble absorbing bile acids before trying cholestyramine.

EXPERT PICKS: WHAT TO READ NEXT

• IBS vs. IBD: Learn the difference between irritable bowel syndrome (IBS) and inflammatory bowel disease (IBD). 

• How the mind can affect the gut: Learn more about the relationship between IBS and anxiety. 

• The worst foods for IBS: A dietitian explains the most common trigger foods for people with IBS.

How long does it take for cholestyramine powder to help with IBS?

It can take several days for cholestyramine to have an effect on your stools.  

Most people take 4 g of cholestyramine powder mixed with liquids each day. But you can adjust the amount based on how well you respond to the medication. Some people may need to take less while others may need to take more. It’s important to work with your healthcare team to find the right dose for you. 

What are the risks of using cholestyramine powder for IBS?

The most common side effects of cholestyramine are: 

• Constipation

• Bloating

• Upset stomach

• Vomiting

• Diarrhea 

• Heartburn

• Loss of appetite

Rarely, cholestyramine can cause serious side effects like bowel obstruction. Very high doses of cholestyramine can lower vitamin K levels and cause bleeding. 

Can cholestyramine powder be combined with other IBS treatments?

Yes, cholestyramine can be combined with other IBS treatments. Based on your symptoms, your healthcare team may recommend trying therapies for IBS-D, including:

• Antispasmodic medications to reduce abdominal pain

• Loperamide to slow down intestinal motility (gut movement)

• Tricyclic antidepressants to relieve abdominal pain and slow motility

• Rifaximin to reduce bloating and diarrhea

If you don’t respond to these medications, your team may recommend a newer therapy like alosetron (Lotronex) or eluxadoline (Viberzi).  

Who should not take cholestyramine powder for IBS?

Cholestyramine isn’t safe for everyone. You can’t take cholestyramine if you have:

• Severe hypertriglyceridemia

• Complete biliary obstruction

• Phenylketanuria

Your healthcare team may recommend a different treatment if you have a bleeding disorder or are at higher risk for bleeding. 

Talk with your healthcare team if you’re pregnant or nursing. Cholestyramine is a category C medication. It may be safe, but there’s limited information on how it affects human fetuses. Your healthcare team can review the risks and benefits of cholestyramine and help you decide if it’s the best choice for you.

Frequently asked questions

Why trust our experts?

Written by:

Christine Giordano, MD

Christine Giordano, MD, is board-certified in general internal medicine. She received her medical degree from Rutgers New Jersey Medical School and completed residency at Thomas Jefferson University.

Edited by:

Patricia Pinto-Garcia, MD, MPH

Patricia Pinto-Garcia, MD, MPH, is a medical editor at GoodRx. She is a licensed, board-certified pediatrician with more than a decade of experience in academic medicine.

Our editorial standards

Meet our experts