defecation vs shits

defecation

noun
  • The act or process of voiding feces from the bowels. 

  • Any of several processes for the removal of impurities, or for clarifying various materials. 

shits

noun
  • Synonym of diarrhea. 

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