dyspepsia vs stomachache

dyspepsia

noun
  • Any mild disorder of digestion, characterised by stomach pain, discomfort, heartburn and nausea, often following a meal. 

stomachache

noun
  • A pain in the abdomen, often caused by indigestion. (The pain is usually lower than the stomach and related to the intestines.) 

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