This just goes to show that everybody isn't the same.
I use about 20 ounces of milk and 2TBS of natural peanut butter in my shakes and doesn't bother me at all.
Also I eat dry roasted walnuts everyday along with cheese and neither one of them bother me either.
Like already mentioned spicy foods kill me which is why I run from them. I don't eat junk carbs, only complex carbs so I'm not even sure what they would do to me. On a side note sweet potatoes bother my stomach also. The sorbitol from my sugar free syrup was bothering me also.
Oddly enough certain vegetables bother my stomach, but I can eat a 30 ounce porter house steak and it does nothing to me.
Asparaus and carrots rip my stomach up. Of course I love eating them but its not worth the risk.