Hello, my name is David Sanders and I am the Professor of Gastroenterology here at the Royal Hallamshire Hospital and with the University of Sheffield, United Kingdom.

The question that I would like to pose is: How common do you think bile acid diarrhoea is? And the answer that I would suggest is that I think bile acid diarrhoea affects more than 1% of the population. So I hope in the next few slides that I can show you the evidence for this.

As we know, to look for bile acid diarrhoea you need a SeHCAT scan and you need to show evidence of a failure for retention. So this slide clearly demonstrates the pathway that is required.

IBS is very common. It affects something like 5–15% of the general population and we’ve used these historical criteria which are updated called ‘The Rome Criteria’, but the thing that has puzzled me always is, it is one of the unique diagnoses where we do not necessarily undertake tests and we are encouraged to make a positive diagnosis on the basis of symptoms.

Now, I completely accept, as you can see from this slide, that there are a number of clearly validated pathophysiological mechanisms for IBS. But what has always troubled me is, Why is it that our treatments don’t always work in individuals with IBS?

In the United Kingdom, 40% of our outpatient workload or more is related to IBS-type symptoms and I want to be very clear in differentiating this. People with IBS-type symptoms I think, may have other diagnoses or diseases lurking within them, and I think that if we carefully investigate our patients, then we are left with a smaller group with whom we can conclude that they have IBS and I hope that then the existing treatments will be of more benefit to those patients. I think at the outset if you have IBS-type symptoms, this is a very mixed or heterogenous group.

Let’s look at this slide as an example. Here, we can see a systematic review looking at chronic diarrhoea or individuals with IBS-type symptoms, diarrhoea predominant.

What the investigators have done is put together a large number of international studies, in total of cohort of more than 1,000 patients, and they found that the prevalence of bile acid diarrhoea is lying about 30% and I accept that there are some inherent weaknesses in this dataset, but I think it’s giving you a signal.

In this slide that I’ve compiled, I’ve shown you three different data sets, from three different investigator groups and all are finding the same thing. When retrospectively looking at individuals with IBS-type symptoms, they are finding a high prevalence of bile acid diarrhoea. So much so, that it led us to undertake a prospective study. This was a dual centre study between Sheffield and another city in the United Kingdom, Leeds where we prospectively and sequentially investigated individuals who presented with IBS-type symptoms and the headline is this: 25% of these individuals had bile acid diarrhoea as the underlying cause for their IBS-type symptoms.

We are not the only investigators to have shown this. The Gothenburg group in Sweden have come up with a very similar data set recently published and furthermore they have shown symptomatic response when they intervene with bile acid replacement therapy.

So, let’s think about this: 5–15% of the population have got IBS-type symptoms. Let’s say 5% and take a lower estimate. A quarter of these individuals have got bile acid diarrhoea. What this suggests to me, is that 1% of the general population have got undiagnosed or undetected bile acid diarrhoea. They are frequently told they have IBS-type symptoms and that is as much help as they get. I would suggest, that when we see individuals with IBS-type symptoms, our first line of investigation should be to look for bile acid diarrhoea.

So I would conclude, I think there is evidence to suggest that at least 1% of the population have got bile acid diarrhoea and the question I would ask is, Does this change your clinical practices and are you the generation of clinicians who consider detecting diagnosing and recognising this currently relatively undiagnosed condition? Thank you.