excretion vs purgative

excretion

noun
  • Something excreted in that manner, especially urine or feces. 

  • The process of removing or ejecting material that has no further utility, especially from the body; the act of excreting. 

purgative

noun
  • something, such as a substance or medicine, that purges; laxative 

adj
  • purging 

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