feces vs urine

feces

noun
  • Digested waste material (typically solid or semi-solid) discharged from a human or mammal's stomach to the intestines; excrement. 

urine

noun
  • Liquid waste consisting of water, salts, and urea, which is made in the kidneys, stored in the bladder, then released through the urethra. 

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