Breaking down the functional and organic paradigm

The most prevalent symptoms arising from disordered colonic function are altered bowel habits, commonly associated with abdominal discomfort. These symptoms can arise from a variety of different disorders that are traditionally classified into those of organic and those of functional etiology. In principle, disorders are referred to as functional when no specific structural, physiologic, or biochemical marker can be identified, although in practice, the search for markers is limited to endoscopic, radiologic, or histologic evidence. Generally, it is assumed that patients with functional colonic disorders suffer primarily from psychologic distress or psychiatric ''comorbidity.'' Due to a lack of specific biologic markers, symptom criteria have been developed that are thought to define distinct syndromes. I propose that in view of recent breakthroughs in our understanding of how the neuroendocrine control systems respond to perturbations of the external and internal environment of the organism in the form of the generalized stress response, the traditional separation into organic and functional is no longer appropriate. Instead, a concept is proposed in which disorders of the colon range from distinct patterns of alterations in the bidirectional dialogue between the central nervous system and the colon.