I am very interested in the recurring theme of waste and how personal and revealing it is. In Underworld, we saw that Marvin hid the smell of his waste from his wife because it was something he found very personal and secret. Waste had the power to display a person totally.
In Infinite Jest the characters take it one step further. Its more than just hiding their waste now. Now characters are actively trying to fabricate their waste through buying urine. They understand how their waste can reveal their secret of drug use, so they must falsify their waste. This kind of becomes a problem however about how revealing waste can be.