Lots of ingridients -
https://gardein.com/products/beefless-burger/
water, soy protein concentrate*, vital wheat gluten*, expeller pressed canola oil*, onions, soy protein isolate*, methylcellulose, yeast extract, onion powder, malted barley extract, garlic powder, dehydrated garlic, organic cane sugar, natural flavor (from plant sources), organic ancient grain flour (KAMUT® khorasan wheat, amaranth, millet, quinoa), sea salt, potato starch, spices (contain celery seeds), white distilled vinegar, natural smoke flavor, spice extracts, pea protein, carrot fiber, beetroot fiber, molasses, wheat starch, soy lecithin.
I had some minor stomach upsets with going vegan. I'd suggest trying another brand and see what happens. Could be the wheat.