Why 100,000 poop photos may bring the next big thing in fitness tracking

David Hachuel wants pictures of your poop -- for science. The computer scientist-turned-entrepreneur is working to build the world's largest database of human stool photos -- up to 100,000 in all. The images will be used to teach an artificial intelligence to tell the difference between stool that's consistent with good health and stool that could be evidence of gastrointestinal ailments like irritable bowel syndrome or Crohn's disease. The color, shape and consistency of stool hold important clues that help doctors make diagnoses. Hachuel thinks the photos can form the basis of an app that nonphysicians can use to obtain such information on their own.