Psychosocial factors have a complex relationship with gastrointestinal illness. Early life factors can contribute to illness susceptibility and condition later illness experiences and behaviors. Existing psychosocial factors, gut physiology and pathology are not associated in a linear or causative fashion, but instead interact to determine symptoms and illness behavior. Investigation of the clinical outcome of these disorders, an area of recent interest, involves both 'hard' (i.e., disability, healthcare use, costs) and 'soft' (i.e., physical and psychologic status and function, health-related Quality of Life) endpoints. In this article I present a biopsychosocial framework for understanding these integrated relationships which are supported by recent data involving both functional and structural (i.e., 'organic') gastrointestinal disorders.