Foods and Gerd

Hi!  This may seem like a crazy question, but I am trying to figure out which foods are causing me problems.  How long after eating a food would a food allergy/intolarance/heartburn occur?  How can you tell if it's something you ate the day before or more recently?  I'm beginning to think I'm having an allergic reaction to some foods, but can't figure out which ones.  I get tightness in my throat hours after my last meal, and sometimes a slight burning in my stomach.  I don't get heartburn.  It does not occur all the time.  When I think I figured out which food (dairy mostly) I try eating it again an nothing happens.  How can you tell?  

I'm scheduled for an endoscopy on Thursday.  Are there any test /biopsies that I can ask the doctor to do to check for allergies/intolarances?

Thanks

[beentrying2quit]

Doctors can test for food alergies (allergies) but my experience is you can do it yourself cheaper it just might take longer.  Check into Celiac's disease or gluten intollerance and see if your symptoms may fit into this category.