Yes, everyone on this board can relate. I technically don't even have IBS (I have problems stemming from a lack of a gall bladder) and stress STILL makes me have worse D problems.
And yes, your doctor more or less accurately described what happens when you have IBS-D (obviously the same hurry-up thing doesn't happen to people with IBS-C). No one knows for sure what exactly is going on in there, but that certainly seems to be what's happening. I don't know that working faster, though, is what causes the fluids--I have always been under the impression that you end up with D when the intestines move too fast because your intestines don't have time to absorb the water and bile that they are supposed to absorb, so it all ends up coming out with your stool.
Nope, no spell check. I'm on a different type of community message board that does have spell check and I have to admit that I've gotten used to it and have to remind myself to read these posts twice to try and cut down on my errors.