CAPTION: Always on the loo?
Until a few weeks ago I’d never heard of bile acid diarrhoea (let’s call it BAD). Despite writing about all manner of tummy upsets for quite a while now – including Irritable Bowel Syndrome (IBS), Crohn’s disease and ulcerative colitis to name but a few – I’d never come across this particular gut nasty.
But then I spoke to Professor Julian Walters, professor of gastroenterology at Imperial College, London, and learned that up to 500,000 people in the UK who have been diagnosed with Irritable Bowel Syndrome – may actually have BAD instead.
Why does it matter? Well, according to Professor Walters, BAD is comparatively easy to treat and there’s a diagnostic test and effective medicine you can take for it – where as the diagnosis and treatment for IBS is far more complicated and seems (to a layman like me at least) to be a more let’s suck-it-and-see-if-it-works approach.
Why don’t more people know about BAD?
I can’t be the only one who is wondering why BAD is not on the radar of more doctors(and patients). By contrast, coeliac disease has become fairly well-known now as has Crohn’s disease. But BAD affects potentially far more people, so why is there is no information about it?
‘Most patients – and doctors – are unaware that bile acid diarrhoea even exists and that there is a diagnostic test and effective drug treatment available,’ explains Professor Walters.
‘IBS is estimated to affect four million adults in the UK; of those 1.3 million have diarrhoea as the predominant symptom. However, its cause is often difficult to diagnose and patients may undergo several investigations, including those for inflammatory bowel disease, colonic cancer, coeliac disease and chronic infections, without a definitive cause being identified or effective treatment.’
Freedom after 48 years
Judith Fulton who I interviewed for the Daily Mail Good Health section http://www.dailymail.co.uk/health/article-2255492/Bile-acid-diarrhoea-For-40-years-doctors-said-I-IBS-In-fact-hormone-problem-cured-simple-pill.html suffered from unexplained daily bouts of watery diarrhoea for over 40 years. She had countless tests including the invasive kind most of us would rather avoid if it isn’t absolutely necessary – doctors just said it was IBS though -and they offered her no treatment.
When Judith read about Professor Walters’ research though it was a light bulb moment and she tracked down his email on the internet and asked him for a consultation. She was later diagnosed with BAD and after treatment with the drug cholestyramine (Questran) her symptoms disappeared within a few weeks. After forty-eight years of suffering she is now free to leave the house without researching where the nearest toilet is. That’s what I call a result and partly why Judith was willing to be interviewed about such an embarrassing health problem – she wants more of us to know about it.
CAPTION: FREEDOM TO GO OUT WITHOUT RESEARCHING THE NEAREST LOO
A bit about bile acid (before we go on)
I won’t bore you with a full blown biology lesson, but in a nutshell: bile acids are essential for digestion and absorption of fats and fat-soluble vitamins in the small intestine. The liver produces large amounts of bile acids which flow into the intestine every day, but only relatively small quantities are lost from the body. This is because approximately 95 per cent of the bile acids are recycled back to the liver from the ileum (part of the small intestine). But in bile acid diarrhoea – bile acid is overproduced and the excess bile passes into the colon causing watery diarrhoea.
Bile acid diarrhoea is also associated with Crohn’s disease, a chronic severe condition characterised by inflammation, ulcers and bleeding that may affect any part of the gastrointestinal tract, including the terminal ileum (the end of the small intestine). This is because Crohn’s causes inflammation and reduces absorption of bile in the intestine and this sometimes necessitates removal of the ileum. This is referred to as bile acid malabsorption as bile is not as absorbed as well in the intestine.
‘In idiopathic bile acid diarrhoea though – patients don’t have a problem with absorbing the normal amounts of bile produced, explains Professor Walters.’Their diarrhoea is triggered by a hormone disorder which causes overproduction of bile and it is this excess bile which causes the diarrhoea – this is an important distinction,’ explains Professor Walters.
Hormone deficiency is the cause
Professor Walters conducted research which found that the trigger for idiopathic BAD (from an unknown cause not related to Crohn’s disease) is a deficiency in a hormone called FGF19, which normally switches off bile acid production when bile acid is reabsorbed.
‘At the moment we don’t know why this happens – it doesn’t appear to be genetic although some patients report their symptoms started after a gastrointestinal infection.’
Unfortunately the symptoms of BAD can be hard to distinguish from diarrhoea caused by IBS.These include up to ten watery bowel movements every day, usually with an urgent need to go and frequently resulting in accidents or faecal incontinence. There is also some bloating and abdominal discomfort.
Diagnosis and treatment
Unlike IBS though, there is a diagnostic test available for BAD. It’s called the SeHCAT test(which stands for selenium-labelled synthetic bile salt) and involves two full body scans seven days apart. In a person with normal bile acid production more than 15 per cent of bile is detectable in the body after seven days, but in people with BAD this figure can be as low as one to five per cent.
Once diagnosed with BAD patients can be prescribed cholestyramine and around two-thirds of patients are reported to respond – although this admittedly may take some time until the correct dosage to control symptoms is found.
CAPTION: What’s really causing your upset tummy?
Hang on a minute though…..
As with many things in medicine though, not everyone agrees. The National Institute for Clinical Excellence, for instance, recently decided although it was’promising’ there was insufficient evidence to recommend the SeHCAT test. Professor Carole Longson, NICE health technology director, said there was also little evidence of the clinical effectiveness of the drugs used to treat the condition and also whether bile acid diarrhoea is a primary or secondary condition.
Professor Nick Read,a gastroenterologist and adviser to the IBS Network is somewhere in between the two camps. He doesn’t believe BAD is a medical condition in its own right – just a symptom of IBS diarrhoea, but on the other hand he says he prescribes cholestyramine frequently to people with IBS where diarrhoea is their predominant symptom and it works really well. He told me:’I find that cholestyramine is an effective drug which mops up bile acid in the intestine. I’ve seen patients who have had diarrhoea for years dramatically improve using this treatment.’
Whatever the mechanism – the upshot is if you’ve had diarrhoea for years and been given an IBS diagnosis and told to live with it, you might want to ask about getting a SeHCAT test. Just like Judith the test (and the treatment) might give you your life back.
Watch Professor Walters here: http://www.youtube.com/watch?v=-O3uR0iDObw
Here’s some more of my articles about gut health you may want to read.