I've read that celiac covers all grains and the gluten diagnosis has been a mistake. Remember that quinoa and buckwheat aren't grains.
BTW be careful about FODMAP, SCD, GAPS and the like. While the information there may be helpful, my avoiding of any minor disturbance backed me into a no carb corner. From there it seemed like my body started to really shut down from the lack of carbs and will test adding them back in right now.
I've started eating grain free because I have Sjogrens (an autoimmune condition) and celiac disease. After over two years on a gluten free diet I wasn't getting better...
Eating grain/dairy free has really been a big improvement for me, I feel like I have a lot more energy, my Sjogrens has died down a lot, and I feel much less inflamed.