It is. They're what hold back
the URINE and feces.
The Big Bang Theory Season 8, Episode 18
passed out in a puddle
of his own URINE.
The Big Bang Theory Season 5, Episode 7
It took me a gallon of URINE
to make that water.
The Big Bang Theory Season 5, Episode 15
that converts URINE
into drinking water.
The Big Bang Theory Season 5, Episode 15
He was so busy figuring out
how many parts per million of URINE...
The Big Bang Theory Season 8, Episode 9