bowels vs innard

bowels

noun
  • The intestines. 

  • The concept or quality that defines something at its very core. 

  • The deepest or innermost part. 

  • Compassion, sympathy. 

innard

noun
  • Entrail; gut; intestine. 

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