If you drink sparkling water for the rest of your life, will your urine fizz?

Answer

No,

the reason is that “fizzy” is dissolved carbon dioxide, which, once in the stomach, immediately leaves the water. The water is then absorbed into the blood and leaves the body mainly through the urine (a little bit as sweat or breath).

You can burp the carbon dioxide. You exhale the bit that is also absorbed into the bloodstream.