PS if you mean the blood test to check for gliadin, I'm not sure. I was always under the impression that it would, but friends have reported over the years that their doc has said they can't always rely on a negative blood test to rule out coeliac diesase.
Anyway, the screen as far as I know is a one off test. I've only ever had two in my life - one to initially diagnose me (prior to biopsy) and one when I didn't get well and consultant #2 wanted to check consultant #1 had made the right diagnosis. Consultant #2 also of course did another biopsy to prove conclusively.
Do they screen your daughter more regularly then? If so, it would be worth asking the consultant whether the test would pick up such low levels. It's sort of irrelevant though don't you think - that test, because surely it's just a snapshot of what her antibodies are doing at that point?
eg if I was tested today, I bet I'd test pos because I've been away for 2 days with work and am unconvinced the hotel's gf food was uncontaminated (cramps that evening). Whereas my annual appt is in Aug and by then, this episode will have passed.
Sorry it's long, but do you see what I mean?
If I've had prolonged ill health in the past I've made an appt with my consultant by calling the hospital and speaking to the people at his clinic, outside of my usual annual visit times. Maybe you could do that, in addition to asking your local doc surgery to run a test for anaemia. To be honest though, my consultant has never really figured out why I get so ill sometimes. My symptoms when they happen are similar to your DDs (also inc depression for me) and last around a month or longer which is why I'm mentioning it.
It could well be something else of course, as it could with me. But I have lived with ill health and coeliac disease since the age of 19. I'm not sure whether, despite my best efforts gluten is getting into my body. Or whether there's something else going on.
I've got to go now (smear - ugh - then collecting DCs) but I'll check back in once the DCs are in bed.