poop oneself vs shit oneself

poop oneself

verb
  • Synonym of soil oneself 

shit oneself

verb
  • To soil oneself. 

  • To be very frightened or astonished (to the extent that one might lose control of one's bowels). 

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