Functional gastrointestinal disorders as a public health problem.

The functional gastrointestinal disorders (FGIDs) are a heterogeneous group of chronic conditions that are considered to be important to public health because they are remarkably common, can be disabling, and induce a major social and economic burden. Despite the Rome consensus process, the line defining true abnormality from health is as yet imprecise. Furthermore, the concept that the FGIDs have no pathological or biochemical correlates is starting to unravel, and some candidate morphometric abnormalities (e.g. duodenal eosinophilia, colonic mastocytosis) have been documented. The quality of care that patients with FGIDs receive is not well understood, despite the high volume of patients seen in primary and specialty care. There are a remarkable number of symptom-based and disease-based co-morbidities that appear to be more common in those with FGIDs that are not alone explained by coexistent somatization. Whether there is any means of preventing the development of FGIDs post-infection is untested but has vast public health implications. Defining disease severity remains key to better understanding the public health impact of FGIDs; severity is probably influenced by the intestinal and extra-intestinal symptom burden, psychological distress and the impact on quality of life, but how these factors interact remains uncertain. An important future research direction must be to quantify at what risk level it is reasonable to prescribe a medication that may be dangerous, and stratify which subsets of patients with FGIDs would qualify for such an approach using objective well validated tools (e.g. based on accurately defining gradations of severity of disease). Finally, there are some reasons to suspect that there may be an increase in mortality in FGID sufferers; for example, unnecessary surgery or invasive testing has a small but not zero associated mortality, and this should be a factor in view of the high prevalence of disease.