I Am Female And 60, Diagnosed With Hashimotos And Diverticultis,

I am female and 60, diagnosed with Hashimotos and diverticultis, impaired glucose tolerance, High blood pressure, chloestrol.
Hemithydroidectomy in 2014,
Since changing my diet last year to include more fibre and less sugar, I have had unwell feeling in my stomach and increased bowel movements.
My son 34 has been a Coeliac for 6 years when he is home I cook for him and eat the same, when he does I start to feel unwell again. I starting to think I have a gluten intolerance.
My brother 59 also has Coeliac Disease for past 12 years