False Negative?

[Maya142]

A friend's 12 year old son is being worked up for IBD. He has diarrhea that wakes him up at night and sometimes has blood in it. Plus, his father has Crohn's. They just did Fecal Calprotectin and it came back very low: <15.6. She was asking if it's possible it was a false negative (and I had no idea). Does anyone know?

I know his ESR and CRP are not elevated, but neither are his father's.

 

[Farmwife]

:bigwave: grace is the same way. Just now after 3 years is her sed rate starting to elevated. her FC as been between 12-70 but never higher.
The GI said early IBD is a lot more difficult to count on numbers.

 

[Momtotwo]

I read about both false negatives and false positives (as in not due to IBD or active infection but elevated) when researching. I will try to find a good study. Basically, the end results was if you tested X number of people by fecal calprotectin to determine if scope needed, you will end up scoping a few who won't have IBD if you only scoped the elevated numbers but you would also miss a small number of people with IBD who didn't get scoped due to low numbers. It's a good test, but it's not diagnostic. I would have been thrilled to have a normal fecal calprotectin for my son. But I would not have ended the IBD work up there.

 

[Maya142]

Yes, M's FC also runs low - we've had as low as 26 (or was it 36?) and as high as 400+ but compared to many of the other kids here, that's not even very high. She was also diagnosed with "early Crohn's". M also has very low inflammatory markers (ESR is usually between 1-4).

 

[Catherine]

Small bowel crohn's is also know for having a lower fc.