Bile Acid Malabsorption: Causes, Symptoms, and How Medications Help

When your body can’t properly reabsorb bile acids, digestive fluids made by the liver to break down fats. Also known as bile acid diarrhea, it happens when these acids spill into the colon and irritate it, triggering watery diarrhea. This isn’t just occasional upset stomach — it’s a chronic condition that mimics IBS but responds to very specific treatments.

Bile acid malabsorption often follows surgery like gallbladder removal, or conditions like Crohn’s disease affecting the ileum — the part of the intestine that normally reabsorbs bile. It can also happen without a clear cause, called primary bile acid malabsorption. People with this issue don’t just have loose stools; they often feel urgent, frequent, and sometimes nighttime diarrhea that doesn’t improve with diet changes alone. Unlike typical diarrhea, it doesn’t usually come with pain or bloating, which is why it’s frequently misdiagnosed as IBS-D.

Doctors test for it using a SeHCAT scan — a specialized nuclear medicine test that tracks how well bile acids are retained — or by trying a trial of bile acid sequestrants. These medications, like cholestyramine, a resin that binds bile acids in the gut and stops them from irritating the colon, are the main treatment. Others include colestipol and colesevelam. They’re not absorbed into the bloodstream, so they’re generally safe, though they can cause bloating or constipation if the dose is too high. What’s key is that if you’ve had chronic diarrhea for months and nothing else worked, this might be the missing piece.

It’s also linked to fat malabsorption — when bile acids aren’t recycled, fats don’t get broken down properly. That can lead to oily stools, weight loss, or even deficiencies in vitamins like A, D, E, and K. You won’t always see these signs, but they’re clues for doctors digging deeper. If you’re on long-term antibiotics, have had radiation to the abdomen, or suffer from unexplained diarrhea after gallbladder surgery, this condition should be considered.

The posts below cover real cases and treatments that connect to bile acid malabsorption — from how drugs like cholestyramine interact with other medications, to how gut health, diet, and enzyme changes can influence digestive symptoms. You’ll find practical advice on managing side effects, understanding why standard IBS treatments fail here, and how to talk to your doctor about testing. This isn’t theoretical — it’s what works for people who’ve been told "it’s just stress" and finally found answers.