I wasn't even obese but I definitely had stomach issues at my highest weight. However, they were not due to my fat stomach, but rather my excessive overeating. I would stuff myself to the point of where I felt miserable; I stuffed myself to the point of not being able to sit up comfortably, let alone sit back or lie down; I would eat things like a whole HUGE bag of chips, five slices of pizza, a whole pint of ice cream, or two or three FULL plates of food when all I needed was one. I had a serious overeating problem that I denied even existed until I was able to look back on it objectively. I'm amazed that I WASN'T
obese... the crazy bit is that my THIN girlfriend often ate just as much as I did (but now that I'm not overeating, she has been overeating much less, too!) and didn't feel nearly as crappy after shoveling all that food down her throat as I did!

What can I say, life's not fair...
I still get acid reflex (and other, um, lovely intestinal things that I DIDN'T get while overweight) if I overeat, but I rarely do it. Thinking of how CRAPPY I'll feel is enough to stop me! Eugh!
I also had no idea that acid reflex was a common side effect of obesity, though it definitely makes sense.