Bile acid malabsorption (BAM) can cause chronic diarrhoea. It is also known as bile acid diarrhoea or bile salt malabsorption. It can happen in people who have had an ileal resection for their Crohn's disease or have ileal inflammation. It can also occur if you have small intestinal bacterial overgrowth (SIBO), coeliac disease and chronic pancreatitis, among other reasons.
What is bile acid malabsorption?
BAM can either be the result of your body producing too much bile acid (or bile salt) or it can be as a result of gastrointestinal disease - such as Crohn's disease.
In Crohn's disease BAM occurs when your ileum (the last part of your small intestines) is unable to absorb bile salt which is released by your body to digest food as it travels through your small intestine.
If you aren't able to absorb the bile salt then it moves into your colon. Your body then sends water to the colon and this causes diarrhoea.
How is bile acid malabsorption diagnosed?
A SeHCAT scan is most commonly used to confirm the diagnosis of BAM. Two scans are taken - normally around a week apart. You will be given a pill to swallow which has bile acids in. The scans will then measure how much of this bile acid remains.
BAM is fairly common in Crohn's disease, but is not always diagnosed as the diarrhoea is believed to be happening as a direct result of Crohn's (diarrhoea is a symptom of Crohn's for many people).
How is bile acid malabsorption treated?
There are a few medications available for bile acid malabsorption. These medications are not always effective for everyone. These include colestyramine and colesevelam. Some people use loperamide to manage it, however you should speak to your doctor before doing so.