Few human illnesses today are so challenging, medically, scientifically, and socio-economically, as the "nonspecific" inflammatory bowel diseases (IBD): ulcerative colitis and Crohn's disease. Originating several centuries ago but essentially diseases of the 20th century, often attacking children and young adults, involving all bodily systems as well as the gastrointestinal tract, ulcerative colitis and Crohn's disease have emerged in recent decades as among the more "glamorous" unsolved diseases, presenting unusual opportunities for insightful clinical and investigative study. Many of the...