do it vs go to the lavatory

do it

verb
  • To urinate. 

  • To be appealing or suitable. 

  • Used other than figuratively or idiomatically: see do, it. 

  • To have sex; make it. 

  • To do something exceptionally foolish or unacceptable. 

go to the lavatory

How often have the words do it and go to the lavatory occurred in a corpus of books? (source: Google Ngram Viewer )