Maybe it was the actual getting up and moving part that got everything going.

Your body needs to make room - hence the "eat-->poop" sequence.

I’ve been constipated for a couple days. Since last night I’ve had that familiar “it’s almost time” type feeling but with no success. I haven’t been very hungry, but while sitting at my desk I decided to go prepare myself a snack. I got the contents out of the fridge and got ready to prepare the snack when, all of a sudden, well, you know. That was all it took. Does just the thought of eating kickstart the digestive process?