The relationship between obesity and functional gastrointestinal disorders: causation, association, or neither?

It is possible that functional gastrointestinal disorders (FGIDs) and obesity have more in common than merely sharing high population prevalence. Epidemiologic data indicate that obesity is associated with chronic gastrointestinal complaints, many of which overlap with FGIDs such as irritable bowel syndrome or dyspepsia. This raises the possibility that obesity and FGIDs may be mechanistically linked. In this paper, we review and summarize the literature linking obesity and FGIDs, comment on the clinical relevancy of existing data, and suggest next steps for future research in this field.