Prevalence of biliary acid malabsorption in patients with chronic diarrhoea of functional characteristics: a prospective study, Flores et al, 2021

BAM! to ideas of functional illness (Bile Acid Malabsorption, that is.)

BAD (Bile Acid Diarrhoea)

Seems like the detailed physiology is fairly well understood:

Of course, every participant who didn't qualify for the Type 2 BAD diagnosis was left in the functional illness bucket.

Cos, well, now that we know about bile acid diarrhoea, of course we know all that there is to know about possible causes of diarrhoea...


And this one is important - doing the test early rather than slapping a functional diagnosis on someone is thought likely to reduce subsequent healthcare related costs, not to mention opening up treatment possibilities:

 

Here's a 2020 BMJ paper on this:
https://fg.bmj.com/content/early/2020/09/22/flgastro-2020-101436
Bile acid diarrhoea: pathophysiology, diagnosis and management

 

BAD is a treatable disease, however, the delay in diagnosis causes a significant increase in the diagnostic care cost as well as affecting the quality of life of patients.​

Also true for currently untreatable diseases. Early diagnosis and generic management alone are highly desirable goals, even in the absence of treatments. Just knowing what the problem lets patients maximise what choices they do have.

Very good to see this message getting into the peer-review literature. Anything that delays diagnosis and treatment/management will increase morbidity and (where applicable) mortality rates.