Pre-primal I didn't get indigestion after a meal, ever. (I got gas and bloating instead!)

However, now, I get it all the time. I notice it's especially bad after a meal out, where I've had no control over ingredients, and even though I've avoided grains or sugars, seemingly I haven't controlled the oil that the food is cooked in. Is it the oil that's causing it?

I went to the best restaurant in my city a few nights ago - so you would think that they would use quality ingredients - I chose a 'Paleo' meal. And, that night, I had the dreaded indigestion again.

What is causing it?

Am I just more sensitive to certain things now I'm on a cleaner Primal diet? Is it the bad oils? Or something else?