bellyache vs stomachache

bellyache

noun
  • Any pain in the belly, stomach, or abdomen. 

verb
  • To unnecessarily complain or whine, often about simple matters. 

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 bellyache and stomachache occurred in a corpus of books? (source: Google Ngram Viewer )