From baby's colic to an older child's complaint of "my tummy hurts," abdominal distress is painful for kids and worrisome to parents, ranking second only to upper respiratory tract infections as the most common reason for non-routine visits to the pediatrician. In many cases, the discomfort is easily remedied and even prevented -- but some kinds of pain indicate a more serious affliction. How can parents make the distinction?

Drawing from more than...