One of the commonest complaints attending man from the cradle to the grave is abdominal pain. To enumerate the array of causes for such pain is not the province of this paper, but, in general, they originate not only from intrinsic disorders of the abdominal viscera but also from lesions of the thoracic viscera, spinal cord and peripheral nerves, and the more remote brain. It is the very multiplicity of these causes which often makes differential diagnosis difficult and elusive. There is a small group, sufficiently large however and inadequately recognized to warrant further emphasis, in which the abdominal pain may have been present over varying periods of time without a demonstrable organic or psychogenic cause having been unearthed by the usual methods of study. What heretofore may have been considered unexplained abdominal pain obviously must have an explanation, and it is suggested that where this variety of pain exists