Maybe check out some antacids or something. For sure don't go out on a full stomach with greasy fried chicken in it. I know that first hand. I once stopped midway on a 100 mile ride and bought some fried chicken. The next 20 miles or so were miserable. Thankfully my stomach settled down for the last 30.

I usually start my rides on a mostly empty stomach as far as solid food. If I do eat prior, I usually just eat carb's and avoid high amounts of fat and protein.