ordeal vs painful experience

ordeal

noun
  • A painful or trying experience. 

  • The poisonous ordeal bean or Calabar bean 

  • A trial in which the accused was subjected to a dangerous test (such as ducking in water), divine authority deciding the guilt of the accused. 

painful experience

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