i agree to a point. i also feel like "ibs" is a name given to a collection of symptoms - i think that's actually the definition of a syndrome, as opposed to a disease - but it seems like it's just a clinically hypersensitive stomach. just like some people get headaches more easily that others, or are more sensitive to pain, we have *very* sensitive and reactive digestive systems. coffee upsets 'healthy' stomachs, too - ours, just moreso. this doesn't mean the pain isn't sometimes very severe, and it doesn't mean that it's all in our heads. it's a fact of our bodies that we have to live with. even before ibs, i always held nervousness in my stomach. i have a friend whose anxiety manifests as asthma.
i think it's important to remember that this isn't just in our heads, something we're imagining - of course, our emotions and thoughts impact our bodies. it's all part of the same thing. but that doesn't mean that our minds are weak, or wrong, or bad, or that we can think our ways out of this any more than we could use our minds to mend a broken leg. this is just how we work, and we have to do our best to make it better.