FGF19 and C4 shown to be reliable biomarkers for Bile acid diarrhoea. Do we need to measure them together all the time or separately to rule out bile acid malabsorption?
I am not a subject matter expert for answering this question but you may want to search NIH NLM's PubMed for information. For example, I found this 2019 publication (free full text access) on "Methods for diagnosing bile acid malabsorption: a systematic review."Article Methods for diagnosing bile acid malabsorption: a systematic review