The voltage delivering 1 watt depends on how many amps are present. We use watts to measure power (P), and amps (I) times volts (E) equals watts.
The urea and water that make up urine are removed from the blood in  the kidney. This is then passed on to the bladder which will be  excreted as urine.
The urea is then removed from the body by the kidneys, in a separate process. As urea is produced, it leaves the liver in the bloodstream and passes via the system to all parts of the body. If it builds up, it may have the effect of a on the body.