I disagree strongly with StephanieL. Many GI's, including ours who is nationally recognized, no longer recommend/require a biopsy to confirm celiac when the tTG is over a certain level. There are so many reasons not to do a challenge. Putting the child back on gluten may harm her physically, it will certain do a number on her mentally - "Mommy told you eating gluten would make sick, but now you have to eat it again and put up with the pain in your tummy" - and it may have a big impact on your parent-child relationship: how she trust you when you force her to do something that will make her fell sick and cause her pain? We were lucky enough to speak with Dr. Joseph Murray of the Mayo Clinic not too long after our son was diagnosed. He said one reason NOT to do a gluten challenge is that celiac children often start to grow, both physically and cognitively, after they stop eating gluten, and a gluten challenge during periods of rapid growth is particularly harmful as it may disrupt or derail the growth. From your post it seems that your daughter is gradually feeling better gluten-free; with a tTG >250 I would expect it's going to take a while for her to feel "normal" again. She's been seriously ill even though she didn't look sick. Anxiety: my son has serious malabsorption secondary to celiac, and he's been gluten-free more than a decade. We saw a neurologist a couple years ago, and one of the tests he did was a complete amino acid profile. Turns out one of the things my son wasn't absorbing was an amino acid linked to anxiety and brain function. Within a week after he started on specific amino acid supplements his anxiety level dropped by 90%. Part of your daughter's anxiety may be organic, a result of her inability to absorb sufficient nutrients - another reason to let her gut keep healing and NOT do a gluten challenge. Your daughter should see a GI and have a complete nutritional assessment. That means reviewing her growth since birth (so bring records), evaluating her diet for nutritional gaps and bloodwork to assess her vitamin levels and determine what supplements she may need to catch her up to normal, healthy levels. At some future point you may want to consult a immunologist to evaluate whether her vaccinations "took" and she developed immunity. Anecdotally I know many celiac kids whose didn't, including my son. Finally, find a support group and help her connect with other celiac kids. That alone may alleviate her anxiety about being celiac.