Little is known about how the gastrointestinal system responds to stressful events or how the gastrointestinal, cardiovascular, and autonomic components of the stress response may be related. In the proposed study, participants will be exposed to laboratory stressors with known effects on the autonomic nervous system while gastrointestinal, cardiovascular, and autonomic-cardiac function are simultaneously assessed. This methodology will be used to determine the specific patterns of autonomic nervous system activity that may contribute to gastrointestinal and cardiovascular stress responses. Further, this methodology will be used to evaluate the relationships between subjective and physiological response systems during periods of stress. The proposed research is relevant to public health issues for two primary reasons: (1) altered gastrointestinal, cardiovascular, and autonomic function are common features of a number of anxiety disorders and (2) stress and anxiety are thought to play a role in the development and maintenance of several gastrointestinal and cardiovascular disorders.