according to Collins (Canadian J of Gastroenterology, 2001) 5-ht4 agonists accelearte transit and facilitate defecation - this from the actual article and not just the abstract sounds like a pretty direct action to me?my understanding of uptake inhibitors is that they remove particles so they don't reach the receptors and so other particles can fir into the receptors and the receptors, particles, and inhibitors are all part of one system? I'm sure there's someone on the bb who's actually taken a course in basic neurophysiology that might shed some light on this whole thing.tom