Trying to understand the difference between blood and stool results
 

I am sorry for this question which I am sure has been asked 1 million times but I don't understand. So, if someone has a positive AGA IgA and a positive Anti-tTG blod test, one could be pretty sure they had celiac (I know about the "gold" standard biopsy). However, if one had those same positive stool test then they cannot assume they have celiac? This is what I keep reading "Serology for anti-tTG antibodies was initially reported to have a high sensitivity (99%) and specificity (>90%) for identifying coeliac disease; however, the systematic review found the two tests were similar"....but I don't understand why a stool test wouldn't be the same result. If there is anti-gliadin and anti-Transglutaminace in the stool, wouldn't it still be a pretty high probability for CD?

I'm not going to change my daughter's GF diet but I am just trying to understand for own understanding.

My doctor indicated that if you were in the grey zone with the blood test it was usually necessary to have the biopsy done. When my tests came through my levels were above the scale, so my doctor suggested that the biopsy was not needed.

After about two weeks gluten-free it was obvious that I was a Celiac.