flush toilet vs shit bowl

flush toilet

noun
  • A toilet that uses water to flush urine and feces through a pipe to another location, typically a sewer main in urban settings or a septic tank elsewhere. 

shit bowl

noun
  • A bowl used for defecation: a chamber pot or toilet. 

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