Is There a Doctor in the House?

Let's say you have world-class pee-holding abilities, and don't 'go' for 8 hours or more.

If you had a lot of caffeine early in the day, but then did not 'go' for many hours after...

Can what's left of the caffeine in your urine, in the bladder, affect you even in a small way as if it were newly ingested caffeine?

My vote is "no", but I'm not a doctor.

Thoughts?