Let’s talk about bile acid

Hello. I thought it would be nice to talk about bile acid today, are you with me?

todaysnewsgraphicBile acid diarrhea is also known as BAD. Perfect acronym, right? You might have BAD if you have been experiencing IBS-D like symptoms: chronic diarrhea, urgency, incontinence, bloating and discomfort. Unfortunately, bile acid diarrhea or malabsorption of bile is an under recognized problem–often not on the radar of many gastroenterologists or primary care doctors.

I have been talking about bile acid malabsorption and diarrhea with some top GI docs around the globe. Trying to learn from the best so I can provide new and updated findings on this topic. Perhaps, for some of you, this post may provide valuable information as you attempt to connect the dots between your symptoms and potential causes. Because GI problems, truly, can be one big puzzle with many overlapping puzzle pieces.

What is bile acid? There are primary bile acids formed in the liver: cholic and chenodeoxycholic acid and secondary bile acids produced from primary bile acids deoxycholic (created by from cholic acid) and lithocholic acid (created from chenodeoxycholic acid). Before the primary bile acids are secreted into the digestive system,  they are conjugated (combined) with either of the amino acids glycine or taurine. This conjugation process makes them less toxic. Conjugated bile acids have a key role in absorption of fats. Conjugation is a very important step in bile acid synthesis converting weak acids to strong acids.

Bile acids play a key role in absorption of fat in the small intestine. They are released from the gallbladder into the bile duct when you start eating a meal. A good analogy: bile acids act like Dawn dishwashing liquid–help breaking down fat into small globules, allowing the fat to be digested!

Normally, about 95% of the conjugated bile salts are reabsorbed in the terminal ileum and returned to the liver via the portal venous system, a recirculation process known as enterohepatic circulation; only a small proportion (3-5%) are excreted into the stool. When bile acids are NOT re-circulated, they arrive in the colon. Bile acid in the colon increases the motility of the colon and draws water in contributing to diarrhea, bloating and urgency.

Have I lost you yet? I hope not!

Bile acid diarrhea can be misdiagnosed as IBS-D.  There are several reasons how and why bile acids may wreak havoc.  

Bile acid diarrhea can result due to overproduction of bile acids, malabsorption of bile acids due to intestinal re-section, or due to small bowel bacterial overgrowth where the bacteria de-conjugate the bile acids, rendering them inactive.  There are three types of bile acid diarrhea:

Type I:  When the terminal ileum, the site of reabsorption of bile acids is removed or surgically by-passed reabsorption of bile acids is altered.

Type 2: no definitive cause found also known as primary bile acid diarrhea.

Type 3: May occur with SIBO, post gallbladder surgery, radiation enteritis, chronic pancreatitis.

I asked Dr. Julian Walters, professor of gastroenterology at Imperial College London to share his expertise on bile acid diarrhea, “Bile acid diarrhea is most common in its idiopathic (primary form) where there has been no previous surgery and no obvious intestinal or other disease.  This is usually then diagnosed as chronic functional diarrhea or irritable bowel syndrome.  Recent work suggests that there may be excess formation in the liver of bile acids and this can be more than can be reabsorbed fully.  Liver synthesis of bile acids is controlled by a newly identified hormone,  FGF19 (fibroblast growth factor 19) and patients with bile acid diarrhea have lower levels of this hormone which can lead to making excess bile acids. Primary bile acid diarrhea accounts for a third of patients with diarrhea-predominant IBS.  This will be about 1% of the overall population.  Diagnosis can be a problem in the US.  People get loose, watery bowel movements, an increased frequency (up to 10 times/day), an urgent need to go, and sometimes fecal incontinence. This leads to fears which affect social life, work opportunities and so on. Current treatments rely on binding excess bile acids in the bowel with drugs such as Cholestyramine. Research is looking at new ways to affect the FGF19-bile acid synthesis pathway.”

Dr. Michael Camilleri, a world renown researcher and gastroenterologist at Mayo Clinic in Rochester, Minnesota shares his update on testing for bile acid diarrhea, “Mayo Clinic has made available through Mayo Medical Labs a test to diagnose bile acid diarrhea/malabsorption. This total fecal bile acid excretion in 48 hours can be performed on the same collection for fecal fat estimation.  Thus, when the doctor needs to investigate the cause of chronic diarrhea, one 48 hour collection performed while ingesting 100 gram fat diet will provide both estimates of fat and bile acid malabsorption. In the next year, it is anticipated that Mayo Medical Labs will launch a fasting blood test to screen for bile acid diarrhea based on the rate of synthesis of bile acids in the liver (serum C4). There is accumulated evidence that 25-40% of patients with chronic functional diarrhea or IBS with predominant diarrhea have bile acid malabsorption.”  

July 15, 2018 UPDATE: Mayo Clinic has finally 3 years later…launched this testing!! Learn more here.

I look forward to better testing than collecting poop for 48 hrs…which, really doesn’t sound like fun!

How do you treat bile acid diarrhea? If there is a correctable disease such as small intestinal bacterial overgrowth or celiac disease, treating the underlying condition is the first step to managing bile acid diarrhea. But often, the cause is not determined so a trial of bile acid sequestering medications might be prescribed. A side effect of bile acid sequestrants is constipation so titrating them to the ideal dose for you body is key. Also, bile acid sequestrants can contribute to malabsorption of some medications and vitamins so be careful to  time dosage accordingly. It is advised that other drugs are taken 1 h before or 4–6 h after taking a bile acid sequestrant.

Three bile acid sequestrants include: colestipol, cholestyramine and colesevelan are on the US market. Dr. Sue Kelly, gastroenterologist at Beth Israel Deaconess Medical Center makes a key point,  ” Stop taking the bile acid sequestrant if constipation develops. You can always start at lower dose and titrate the amount up.” Finding the proper dose is very individual with bile acid sequestrants.

Dr. Kelly provides some tips, “Colestipol is a large pill, so it may not be the best option if you have trouble swallowing big pills.  Start with one pill. Some people need up to three per day and some need it only 2-3 times per week.” Cholestyramine (Questran) is a gritty powder that is taken daily. Dosing varies per person 1/2 a packet might work or some individuals use up to 3-4 packets per day!  Start slow and titrate up!

 A great review article on bile acid diarrhea can be found here! And another article by Dr. Walters here! These are medical/research articles though…not designed for the consumer but still has valuable information.

Of course, not all diarrhea is bile acid induced!

Osmotic diarrhea is associated with FODMAP intake.  FODMAPs are very small carbohydrates that are commonly malabsorbed. The small size of FODMAPs contributes to their ability to pull water into the intestine.  Secretory diarrhea can result from bacterial toxins, reduced absorptive surface area caused by disease (celiac disease) or intestinal resection,  laxatives over-use, drug side effects and medical disorders that reduce intestinal function. 

If unrelenting diarrhea is stopping you in your tracks, discuss the possibility of BAD with your gastroenterologist!

21 replies on “Let’s talk about bile acid

  • Pauline

    Thanks so much for this article Kate, I shall be taking it to my GP with me. It’s something I discussed with Emma a while ago.

    Pauline (patient of Emma Carder’s)

  • Sandy

    What about too little bile acid? I have IBS-C. If I take ox bile with meals I digest a lot better.

  • Ann

    Nice article today! I have experienced severe IBS this past year and probably over the years. I am taking Lotronix, which is advertised on tv and it started working within 2 days. I was able to take a trip to Minneapolis and not stop every hour! In addition, when I eat meals, I don’t get bloated anymore and I have regular stools daily! Ask your gastroenterologist about this new medication. It is around $850, but with my coupon it was $15.00.

  • Margaret

    I had my gallbladder years ago and had a great deal of diarrhea, but now I have the opposite problem with constipation. I am on a low fodmap elimination now so hopefully this will help.

  • Terri

    Thanks Kate. A few questions…Can occasional, but not daily, motility problems (i.e. diarrhea once a week) be caused by bile acid diarrhea? Is there a diet (low fat?) that helps rather than having to take medications? Thanks!

    • Carol Benjamin

      I have the same type of problem as Terri. I do have acid reflux and would like to know if this is related. I, too, would like to skip medications if possible. I do know whenever I eat a fatty meal, I have diarrhea the following day. Thanks.

    • katescarlata

      Perhaps–if you diet is low enough in fat–it might not trigger a major issue w/ diarrhea. If you notice that diarrhea occurs with a heavy fat meal, maybe. Try to see if there is a pattern to when you have diarrhea–that may help you determine the cause or lead you down the path to determine the cause.


    My Fiancé has been diagnosed with severe BAM (less than 3% is absorbed) after a sehcat test.
    Diet doent help and sequestrants do not even help him to manage the chronic diarrhoea at all.
    He has to go to the bathroom up to 15 times a day everyday. He can’t remember the last time he passed a properly formed stool. The pain and discomfort is unbearable plus the inconvenience of having your life revolve around going to the bathroom.
    We cannot wait for more research to be done. Come on Gastro specialists get investigating! Is it FGF19 hormone is it antibiotics in early life?!

    • katescarlata

      Emma, perhaps there are other reasons in addition to BAM that your fiance is dealing with diarrhea. Could SIBO be an overlapping issue, pancreatic issues?

  • Vivian

    What is the current method of diagnosis? Does a low FODMAP diet help this? I had excess fat in my stool when tested. Could this be the problem?

    • katescarlata

      Vivian –current testing options are limited for BAD in the US. You would have to do a 48 hour stool collection or perhaps, just do a trial of the bile acid sequestrants. Fat can be malabsorbed for a number of reasons– in small intestinal bacterial overgrowth–bacteria render the bile acids inactive–this can be a reason fat is found in the stool. Pancreatic insufficiency is another reason fat is not digested properly. You can screen for pancreatic insufficiency by checking a stool elastase level. Gall bladder or bile acid processing could also contribute to fat maldigestion.

  • Pat Endicott

    Bile malabsorbtion was mentioned by my gastroenterologist before I was referred to a dietician and recommended to try the FODMAP regime. I tried Questran for a few months but had no long term benefit unlike restricting FODMAPs and finding onion & garlic to be the culprits. It’s good to know the good old NHS is doing its job – thanks for the article.

  • Trish

    This looks really interesting, though I’ll have to read it again to take it all in. I also had my gall bladder out about 20 years ago and wonder now if that was a wise decision. But … can’t change that fact so have to work around it. The FODMAP diet has helped enormously with diarrhoea and can deal with the constipation but I still have something else – I often feel “liverish” or out of sorts. Maybe the bile problem is an issue here.

  • Emma

    Thank you for your reply Kate.
    Scott has has stool samples tested (though not where a daily sample was given) and some sort of breath test (sorry can’t remember the name). Specialists have ruled out any kind of bacterial problems. When would they have tested for Pancreatic insufficiency? Is this something he should discuss in his next appointment?
    He has tried the Fodmap diet and finds it quite frustrating as it includes lists of foods that make him worse. The Dietician at the hospital discharged him from her care as eliminating certain foods/drinks do not make much difference to his condition.
    Scott once found that a certain antibiotic (metronidazole for a tooth infection) he was taking stopped the diarrhea for a few days and he did have a regular bowel movement . The diarrhea returned after about 3 days though. This was discussed with the Specialist as Scott thought perhaps this pointed towards it being bacterial & was keen to see if they could investigate it further. He’s read about a specific antibiotic (Rifaximin) prescribed for travellers diarrhea (USA only) that clears up a lot of people with chronic bowel issues, but they can’t prescribe that here for Scott’s condition even though we begged to be able to just try it. I have noticed that his breath often smells sweet or fermented and this has been mentioned to the specialist too. Is it worth going for further bacterial/parasite testing?
    His current specialist has stopped investigations after the diagnosis of severe B.A.M and in the last appointment I attended with him it was heart breaking being told there is nothing they can do for him but he has to learn to live with it!
    He is self employed as a heating engineer and has a toilet in his van so he can at least try and leave the house to go to work. If there are further investigations/test you think might be beneficial or certain areas you think are worth researching we would be very happy to hear any advice you have.

    • katescarlata

      If he responded to the antibiotic for tooth infection…than that tells you something. Rifaximin is often used for small bowel overgrowth–but other antibiotics can be used as well–flagyl, cipro, etc. Testing for small bowel overgrowth is not always accurate—so I would discuss this possibility more with the GP or gastroenterologist. Bile acid diarrhea can be due to small bowel bacterial overgrowth–so this should be thoroughly explored.

  • Marie bueno

    Kate, I had my gallbladder out, what would be precautionary things I should do to prevent these issues.

  • Angie

    Kate, great read! I am a nutrition student who also suffers with IBS, I am wondering if decreasing soluble fiber intake will decrease bile excretion from the body, and maybe reduce the short transit time of my meal resulting in less diarrhea? Also, will decreasing fat in the diet also restrict the amount of bile secreted in the first place?

    • katescarlata

      Great questions, Angie. A reduced fat intake may reduce bile acid release–but some people make more than they need regardless of what they eat. And soluble fiber may help absorb some of the bile acids and help reduce the diarrhea for some folks.

Comments are closed.