You may not have celiac disease but you could still be nonceliac gluten sensitivity. I am very gluten sensitive, but do not have celiac (I do have the genes and Irish bloodline, but not the antibodies. My dr has told me that he has noticed celiac is more common in the Irish, and I am half Irish). Anyway, you could still be gluten sensitive without being celiac. Try a gluten free diet for a month and see what happens. It would mean gluten free bread, bread items, pasta, cereal and anything that is normally made with wheat will need to be gluten free.
There was a coworker who kept having loose stools and everything checked out normal. Finally she went on a gluten free diet and it helped her. She was not celiac either, but was apparently gluten sensitive.