Dear Theri,
It must be difficult for you to see your daughter undergoing many tests and investigations without a specific cause to her symptoms identified.
Anxiety may have medical or psychiatric causes. Stress may also contribute to your daughters symptoms.
It is important to rule out medical causes for her symptoms, as you are doing.
I recommend a referral to a psychiatrist, treatment in the form of psychotherapy or medication could help reduce her symptoms.
Best Wishes to you and your daughter.
HFHS M.D.-SW