Anxiety and gastrointestinal illness.

The substrate for modulation of the gastrointestinal tract by anxiety and other psychiatric disorders is provided by our knowledge of central nervous system control mechanisms of gastrointestinal functions. Recent experiments that examine the gastrointestinal response to acute stress amplify prior work and confirm that central stimuli, viz. emotional stress, can produce measurable gastrointestinal changes. These changes are not uniformly predictable on the basis of knowledge of the control mechanisms, alone. Acute stress experiments cannot be directly extrapolated to anxiety disorders and their relationship to gastrointestinal illness; careful physiologic studies in these more chronic disorders are sparse. Anxiety disorders and other psychiatric illnesses are particularly common in patients with the functional bowel diseases. This heterogeneous group of gastrointestinal diseases remains fertile territory for examining emotion-gut relationship on a biologic level.