What Causes Abdominal Bloating, Diarrhea And Bad Breath?

Hi, I have never been diagnosed with Celiac Disease but I seem to have a lot of the symptoms including bloating with most foods, constant issues with diarrhea and constipation, also I suffer from bad breath that never seems to go away no matter what drastic measures I use what is the best way to find out if I actually am gluten sensitive or that I do have Celiac Disease