Question: Have you ever analysed diarrhoea?

Emma Ashley answered on 14 Mar 2013:

Nope, we do sometimes get these samples into the lab but we can’t measure anything in them. Because diarrhoea has a lot of water in it, it would dilute out the compound we are measuring and would give a false level. We let the doctor know and ask the patient to send another sample that is not diarrhoeal.

In microbiology, I think they may measure bugs in diarrhoea, because if there are certain bugs present, they will still grow no matter how watery the sample is.