There is not enough evidence to recommend routine adoption of SeHCAT (tauroselcholic [75 selenium] acid) for diagnosing bile acid diarrhoea in people with:
chronic diarrhoea with an unknown cause, suspected or diagnosed diarrhoea-predominant irritable bowel syndrome (IBS‑D) or functional diarrhoea
Crohn's disease without ileal resection who have chronic diarrhoea.
Centres already using SeHCAT for diagnosing bile acid diarrhoea may continue to do so but must collect further data or do further research (see section 5).
Further data collection and research are recommended (see section 5) on:
how SeHCAT test results affect decisions about treatment and clinical outcomes
how well tolerated and effective treatments for bile acid diarrhoea are
the health-related quality of life of people with bile acid diarrhoea.
Why the committee made these recommendations
SeHCAT is a test for diagnosing bile acid diarrhoea. Having bile acid diarrhoea can affect quality of life and limit daily activities, such as the ability to work. There is an unmet clinical need for a test to diagnose bile acid diarrhoea. Having a test is important to explain the person's symptoms and offer treatment.
Despite additional research since NICE diagnostics guidance on SeHCAT in 2012, clinical evidence on SeHCAT remains limited in quantity and quality. Most studies are small and give results only for people who had a positive SeHCAT test result. It is unclear how the test results are used to guide management of bile acid diarrhoea, and how well people tolerate treatment. So, it is uncertain how having a diagnosis affects clinical outcomes, particularly in the longer term.
The lack of data on the link between the SeHCAT test and longer-term clinical outcomes means that the economic model includes many assumptions, so its results are not reliable. Because of this, SeHCAT's cost effectiveness cannot be determined, so it cannot be recommended for routine adoption. So, although SeHCAT shows promise, further data collection and research are needed.