Bile Acid Malabsorption: Causes, Symptoms, and Treatment
Medically reviewed by Achuta Uppu, MD, Internal Medicine. Last reviewed: October 23, 2026.
What kind of doctor treats Bile Acid Malabsorption?
Bile acid malabsorption is usually evaluated and treated by a gastroenterologist, a doctor who treats the digestive system. Your primary care doctor can start the evaluation and refer you. A direct primary care or concierge doctor can be a first stop for an evaluation and can refer you to a specialist when needed.
What is bile acid malabsorption?
Bile acid malabsorption (BAM) means your gut cannot take back in bile acids the way it should. Bile acids are made by the liver and help digest fat. They are normally reused after they reach the last part of the small intestine, called the ileum. When they are not reused, extra bile acids reach the colon, or large intestine. The extra bile acids pull in water. The result is chronic diarrhea, which means diarrhea that lasts a long time.
Doctors group BAM into types. Type 1 comes from disease or surgery in the ileum, such as Crohn disease. Type 2 is idiopathic, which means it has no clear cause. In type 2, the liver makes more bile acids than the ileum can handle. Type 3 comes with other gut or pancreas problems. One is celiac disease. Another is microscopic colitis, a type of bowel swelling. It can also start after gallbladder removal. Type 4 is a side effect of metformin, a medicine for type 2 diabetes.
Symptoms
Malabsorption syndromes share some common symptoms. With BAM, the main problem is watery diarrhea. Common signs include:
- Long-term diarrhea, often urgent and watery.
- Greasy, bulky, foul-smelling stools that may float.
- Gas and bloating.
- Abdominal pain, though this is less common in most malabsorption syndromes.
- Unintentional weight loss.
About a third of people with IBS-D have bile acid diarrhea. IBS-D is irritable bowel syndrome with frequent diarrhea. This form of diarrhea comes from too much bile acid in the colon.
Causes and who gets it
BAM can be primary or secondary. Primary BAM results from the liver making too much bile acid. Secondary BAM develops when something blocks the ileum from taking bile acids back in. Causes include Crohn disease in the ileum. They also include surgery or radiation on the ileum, celiac disease, tiny gut growths called small intestinal bacterial overgrowth, microscopic colitis, HIV-related enteritis, diarrhea after an infection, and gallbladder removal. Some malabsorption syndromes can be serious. Many are manageable once the cause is found.
How doctors diagnose it
Doctors start with a history and physical exam. Then they use lab and stool tests. Blood tests can check blood counts, vitamins such as B12 and D, iron, and minerals. Stool tests can measure fat or look for parasites. Doctors may also use breath tests, imaging scans, or endoscopy. Endoscopy uses a flexible tube with a camera to look inside the gut. Many tests for bile acid diarrhea are unreliable or hard to get. So doctors often rule out other causes first.
Treatment
Bile acid malabsorption is usually treated with diet changes. Doctors also give medicines called bile salt binders. Some names are cholestyramine and colestipol. These medicines bind bile acids in the gut so they cannot bother the colon. Treatment also targets the cause, fixes low nutrient levels, and controls symptoms. Many people stop taking the binders because they taste unpleasant. Scientists are working on new drugs for this problem. Malabsorption syndromes are usually not life-threatening. But severe, long-lasting cases can cause serious problems, such as salt imbalances from long diarrhea.
When to see a doctor
See a doctor if diarrhea keeps coming back, or if you have weight loss or greasy stools. Severe, long-lasting cases can become life-threatening. Call 911 if you have severe belly pain, if you faint, if you feel confused or are hard to wake up, or if you have severe diarrhea or vomiting that will not stop.
How a direct primary care or concierge doctor fits in
A direct primary care doctor charges a flat monthly fee instead of billing insurance, while a concierge doctor usually charges more and often works alongside insurance. Either one can order the tests used to make a diagnosis. They can also set up your care with a gut specialist, such as a gastroenterologist.
Common questions
Is bile acid malabsorption the same as IBS?
No, but they overlap. About a third of people with IBS-D have bile acid diarrhea. IBS-D is irritable bowel syndrome with frequent diarrhea. The symptoms feel similar, but the cause is different. Current medicines bind bile acids in the gut.
Can bile acid malabsorption be cured?
It is usually managed rather than cured. Treatment depends on the cause. If it comes from Crohn disease or bacterial overgrowth, treating that condition helps. Diet changes and bile salt binder medicines often control the diarrhea.
What foods should I avoid?
Doctors often suggest a low-fat and low-fiber diet for bile acid malabsorption. Fatty foods can make diarrhea worse. Ask your doctor before making big changes, so you still get enough nutrients.
Why does BAM cause diarrhea?
Bile acids are normally reused after they reach the ileum. When they are not, they pass into the colon. There they cause the colon to release water and salts. That extra water comes out as watery diarrhea.
Sources
- StatPearls, NCBI Bookshelf - Malabsorption Syndromes
- MedlinePlus - Malabsorption Syndrome
- NIDDK - Identifying the distinguishing features of bile acid diarrhea
Medical Disclaimer
This content is for general educational and informational purposes only and is not medical advice. It is not a substitute for professional medical advice, diagnosis, or treatment, and reading it does not create a doctor-patient relationship. Always seek the advice of your physician or another qualified health provider with any questions about a medical condition, and never disregard or delay seeking professional advice because of something you read here. If you think you may have a medical emergency, call 911 (or your local emergency number) immediately.
