The road to Rome.

T he traditional medical diagnosis of disease requires observed anatomical or physiological abnormalities. Description of the disease's symptoms and signs follows naturally. Clinicians can then predict the anatomic diagnosis by recognizing these symptoms and signs in their patients. In the case of the functional disorders, such a process is impossible. Since there are no observed patho-physiological defects, we only know of the existence of the disorders through the words of our patients. The movement to define these disorders of unknown pathology represents a substantial change in thinking for doctors whose training concentrates on basic science and palpable " evidence. " Since more than half of gut disorders encountered by gastroenterologists and primary care doctors are functional, we must face the reality that no current scientific evidence explains these disorders, and develop alternate methods to identify them. For too long, functional diseases were described by what they are not, rather than as real entities. Yet they are real enough to patients. Not only does such an exclusive approach fail to provide the patient with the dignity of a diagnosis, but it also generates needless tests and consultations. The fruitless pursuit of an anatomical cause renders functional disorders " diagnoses of exclusion. " Their very numbers and cost demand a more positive approach. More seriously, there was a disconnect between the subjects chosen for randomized clinical trials (RCTs) and the labels used in clinical practice. Because clinical scientists failed to describe their subjects accurately, the results of their RCTs are of uncertain applicability to the patients encountered by practicing doctors. In a 1988 critique of 43 clinical trials of irritable bowel syndrome (IBS) treatments, Klein 1 observed that 58% of them reported " absolutely nothing about the criteria by which IBS patients were selected. " There were important differences among the remainder, some not requiring abdominal pain, and others not even requiring a bowel habit abnormality. Klein concludes, " Not a single IBS treatment trial reported to date [1988], used an adequate operational definition of IBS. " Table 1 further illustrates this point. Many of these reports were published in prestigious journals and in some cases form the basis of regulatory approval of drugs that remain on national formularies. Most of these reports implied that the diagnosis of their subjects rested solely on the exclusion of structural disease. The trials shown in Table 1 include IBS or irritable colon syndrome (ICS) in …