drop a bomb vs flatulate

drop a bomb

verb
  • To release noxious gas from the bowels: to fart. 

  • To release feces into a toilet; to defecate. 

  • Used other than figuratively or idiomatically: see drop, bomb. 

flatulate

verb
  • To emit digestive gases from the anus, especially with accompanying sound and smell. 

How often have the words drop a bomb and flatulate occurred in a corpus of books? (source: Google Ngram Viewer )