Thursday, 19 March 2015

Crohn's Disease and Bile Acid Malabsorption (BAM)

I have covered this topic a couple of times before. Recently I have seen an increase in the number of questions and comments on IBD forums relating to BAM. I believe that increased awareness would help many Crohn's and IBD patients.

I produced this simple slide, aimed at one particular group of at-risk patients. It's self explanatory.

Right click to copy this image
Here is an extract from a document published by NICE (National Institute for Health and Clinical Excellence)  - "Crohn's disease is sometimes treated by ileal resection. The prevalence of bile acid malabsorption in people with Crohn's disease in clinical remission who have had ileal resection is high (97%)".

My own situation : ileal resection and stoma - October 2010; reversal - June 2011 and clinical remission ever since, confirmed by colonoscopy a fortnight ago. I had expected after the operation, and being in remission, that my digestive system would have returned to pre-Crohn's normality. No. I would often suffer from an "upset stomach" with its attendant rushes to the bathroom. I kept asking myself, and questionioning on this blog, had I eaten something dodgy; picked up a virus or was I undergoing a Crohn's flare?

I mentioned it at each outpatients appointment but it wasn't until Autumn 2014 that my consultant suggested I should undergo a test to confirm if I was suffering from BAM. Of all the tests we get put through this must be one of the easiest. It's called the SeHCAT test and involves swallowing a capsule containing a mildly radio active substance which dissolves and becomes a marker absorbed by your digestive system. You then have two x-rays, one week apart, and the x-rays the analysed to see how much marker remains in your system.

Anything less than 15% of the marker remaining is considered to be malabsorption. My own reult was under 1% which is classified as "severe". There are drugs available to treat the condition. The most common appears to be Questran but some patients find it diificult to tolerate taking it. So far I have managed to keep it under control with good, old Loperamide.

However, since being diagnosed I have found my symptoms have greatly improved, not because of taking new/additional drugs but because I now know what my digestive system is up to and it's not a sign that I'm about to descend into a flare. I feel a lot more relaxed if I do have an upset stomach for a couple of days.

My understanding of the BAM mechanism is that during the digestive process your stomach uses bile acid to break down the food you eat. When the acid/food mixture reaches the last section of the small intestine, the ileum, the acid is reabsorbed and passes back into the biliary system. If you no longer have an ileum the acid passes from the small intestine into the large intestine, causing diahorrea. (The ileum also absorbs vitamins, which is why it is important to supplement them, for instance having regular B12 injections)

I hope, by writing the above, I've managed to convince you to add BAM to the list of questions you ask your consultant/surgeon next time you see them. This is especially important if :

a) You have had an ileal resection and suffer from chronic diahorrea
b) You are about to undergo surgery which could involve ileal resection, especially the removal of the terminal ileum

Please feel free to copy the slide above and pass it on as widely as you can. It might just help fellow Crohn's/IBD patients gain a better quality of life.

When I was doing the research for this post I came across this Research Proposal from Guys and St.Thomas' Hopital. Maybe BAM really will achieve greater awareness in the not too distant future.

Click to enlarge