Why does drinking coffee in then morning sometimes cause immediate evacuation of bowels and/or bladder and other times have no effect?

Question

I know that coffee is a diuretic but I don’t understand why the effects can vary so much day to day

In: Biology

Answer 1

Caffeine and the oils have a stimulate/laxative effect. In the morning, if your stomach is empty and you chug some good old bean juice, you are going to rapidly absorb the coffee and draw a bunch of water into your bowels as well as stimulate peristalsis (make ya poop).

Additionally, caffeine will pull water from the kidneys which will fill the bladder quicker (make ya pee).