If you go to an allergist, you will get multiple small skin pricks along the forearm. This is testing for the immune molecule IgE. This is an immediate immune reaction molecule - meaning you'll react to that allergen within an hour of exposure. You've likely already suspected your reactive foods.
Then there is IgG testing. This is a delayed immune molecule. Meaning that after eating a food, you can have a reaction that occurs anywhere from 30 minutes to 72 hours after consuming a food. Thus it's nearly impossible to determine which foods you're sensitive to.
You can get a test kit at the clinic. It's as simple as a finger poke & then you fill up a small card with a few circles & then mail it off. It's that simple. If you are not able to poke your own finger, you can book a brief appointment, & this can be done in office. If you have any questions, send us an email - firstname.lastname@example.org