Expert Rev Gastroenterol Hepatol. 2010 Oct;4(5):561-7.
Section of Hepatology & Gastroenterology, Department of Medicine, Imperial College London and, Imperial College Healthcare, London, UK. email@example.com
Chronic diarrhea due to bile acid malabsorption may be considered as contributing to the diagnosis when it results from secondary causes, such as ileal resection affecting the enterohepatic circulation. However, the primary form (also known as idiopathic bile acid malabsorption) is not well recognized as a common condition and patients are left undiagnosed. Primary bile acid diarrhea can be diagnosed by the nuclear medicine 75Se-homocholyltaurine (SeHCAT) test, although this is unavailable or underutilized in many settings. A systematic review suggests that approximately 30% of patients who would otherwise be diagnosed with diarrhea-predominant irritable bowel syndrome or functional diarrhea have abnormal SeHCAT retention. Serum 7α-hydroxy-4-cholesten-3-one can also be measured to show increased bile acid synthesis. The reasons for the lack of recognition of primary bile acid diarrhea are discussed, and these are compared with the other common cause of malabsorption, celiac disease. The lack of a clear pathophysiological mechanism has been a problem, but recent evidence suggests that impaired feedback control of hepatic bile acid synthesis by the ileal hormone FGF19 results in overproduction of bile acids. The identification of FGF19 as the central mechanism opens up new areas for development in the diagnosis and treatment of primary bile acid diarrhea.
PMID: 20932141 [PubMed - in process]
But interpretating it one should be very careful, because of forward statements like this.
"A systematic review suggests that approximately 30% of patients who would otherwise be diagnosed with diarrhea-predominant irritable bowel syndrome or functional diarrhea have abnormal SeHCAT retention"
There are very specific symptom clusters for an IBS diagnoses. The word "suggests" means they need to do more work on this to clarify. Not that 30 percent have "SeHCAT retention" and not IBS.