How fast can ibs could the gi tract to move?

I’m diagnosed with ibs and it seems to just be a catch all “we don’t know why you’re pooping like that” diagnosis. I’ve had coloured drinks, broccoli buds and such come back out like 3 hours later and this isn’t something I’ve seen others discuss in relation to ibs and it feels like it could be something else more severe. What is the range of “normal” fast bowels with ibs?