Yea, that's happened to me before, especially lately. I normally have IBS-A so it isn't that bad, but when I get bad Ds, then I can be in pain for at least an hour at a time on and off during the entire day. Pain reliever never helps it, and it always comes with a big urgency to go. The only thing I can do is just sit, moan, and wait for it to pass. Once my body expels whatever is causing it, it normally stops/lightens up.
Sometimes I get it on an empty stomach if I'm gassy.
Dx with crohn's since Oct '04.
Dx with IBS since June 4, 2008.
Have had symptoms since 2000.
About to see a nutritionist... I need help understanding food! :)