abdomen vs bowels

abdomen

noun
  • The cavity of the belly, which is lined by the peritoneum, and contains the viscera; often restricted in humans to the part between the diaphragm and the commencement of the pelvis, the remainder being called the pelvic cavity. 

  • The posterior section of the body, behind the thorax, in insects, crustaceans, and other Arthropoda. 

  • The belly, or that part of the body between the thorax and the pelvis, not including the back; or in some lower vertebrates, the portion between the cardiac and caudal regions. 

bowels

noun
  • The intestines. 

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

  • The deepest or innermost part. 

  • Compassion, sympathy. 

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