system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: When you drink a significantly larger amount of liquid than the average bladder can hold, what does the body do with surplus until it's time to let it go?
gpt
Consumed liquid doesn't immediately find its way to the bladder.  
First, it sits around in the stomach until the stomach contents are sufficiently digested, where the mixture is passed to the intestines. Most of the water is absorbed into the blood stream in the large intestine.  
Once in the blood, the excess water is removed by the kidneys and then passed down to the bladder.

All of these processes take time, and the bladder gradually fills until you feel the urge to urinate.