Stress and the gastrointestinal tract - V. Stress and irritable bowel syndrome

Different types of stress play important roles in the onset and modulation of irritable bowel syndrome (IBS) symptoms. The physiological effects of ps ychological and physical stressors on gut function and brain-gut interactio ns are mediated by outputs of the emotional motor system in terms of autono mic, neuroendocrine, attentional, and pain modulatory responses. IBS patien ts show an enhanced responsiveness of this system manifesting in altered mo dulation of gastrointestinal motility and secretion and in alterations in t he perception of visceral events. Functional brain imaging techniques are b eginning to identify brain circuits involved in the perceptual alterations. Animal models have recently been proposed that mimic key features of the h uman syndrome.