Prior to 1936, Crohn's disease was a rare and unrecognized disease entity. Today, the United States is the midst of a rapidly growing epidemic. It is estimated that between 800,000 and 1.2 million citizens are currently afflicted. The unanswered question is WHY? In the 1990s, circumstantial scientific data inferred a potential causal relationship between Crohn's disease in humans and mycobacterial pathogen in domestic animals, Mycobacterium avium subspecies paratuberculosis (MAP). When it was documented that MAP survived pasteurization and was potentially present in milk, infant formula, and powdered milk, a global precautionary alarm button should have been pushed by those who govern in the public trust. PREVENTION OF CROHN'S DISEASE describes MAP's journey across the zoonotic bridge between animals and humans and the unique circumstances by which it allegedly produces disease.