fistula vs water pipe

fistula

noun
  • A tube, a pipe, or a hole. 

  • An abnormal connection or passageway between organs or vessels that normally do not connect. 

  • The tube through which the wine of the Eucharist was once sucked from the chalice in certain ceremonies (such as papal Masses). 

water pipe

noun
  • A pipe that is a conduit for water; an essential element of plumbing. 

  • A device for smoking, such as a hookah or bong, in which the smoke is drawn through a container of water before inhaling. 

How often have the words fistula and water pipe occurred in a corpus of books? (source: Google Ngram Viewer )