Recurrent abdominal pain is a common complaint among school-age children, being present in up to 15% at any given time. It represents the most common chronic pain entity in pediatric patients. The great majority of these patients will have a functional gastrointestinal disorder (FGID). The most common FGID in these patients is functional dyspepsia (FD), defined as upper abdominal pain or discomfort unrelieved by bowel movement and in the absence of a structural or biochemical explanation for the pain. The etiology of FD is multifactorial, including biological factors, and these factors can be viewed within a biopsychosocial model. Biological factors include inflammation, dysmotility and increased visceral sensitivity. These biological factors are influenced by and are interactive with psychosocial factors such as anxiety, depression and social interaction. This study will evaluate intestinal permeability as a measure of barrier dysfunction and investigate the correlations between increased permeability, mucosal inflammation and anxiety scores to provide further insight into the etiology of FD, thereby assisting in the development and selection of treatment modalities.