Hi all,

I just have a general query about the FIT test.

Every year i order and pay for my own FIT kit. It is analyzed by TDL labs,one of the major UK pathology labs in the UK.

They send me the results within a few days.

Since 2019 i did three tests with them registering 4,19, <4ug in that order with the latest only a few weeks back showing <4ug

The one that flagged 19ug , i queried with my GP and had an NHS fit done which registered 7ug.

I know GPs tend to just tell you positive or negative and i know that NHS England action level is a staggering 120ug

Just thinking about the mechanism of the FIT test, i was curious about how results can be relied upon.

The sample stick just requires a really tiny sample on the end of it. 

Put simply, what if you sample an area of your stool which simply doesnt have any micro blood in it? 

Surely a more definitive test, though somewhat impractical, is to take the whole stool and process it all . In that way we could see that at that time there was undetectable blood in the whole sample.

As it is it looks like we are taking a really small sample and saying there was no blood detected in the immediate area of the small area of total stool that was sampled. Maybe there was blood in the rest of it?

thanks for any comments