The pathophysiology of functional gastro-intestinal disorders remains unclear. A relatively new approach to these disorders has been the study of visceral sensory perception. A decreased pain threshold to intraluminal balloon distension has been demonstrated in patients with irritable bowel syndrome, functional dyspepsia, and non-cardiac chest pain. This altered visceral sensitivity does not appear to extend to somatic sensation; patients have generally had normal sensory thresholds to various stimuli applied to the skin. It is uncertain whether altered gut sensation represents a primary event in the pathogenesis of disease or simply a disease marker. In this review, we examine the evidence of altered visceral sensation and discuss the implications for patient management and drug therapy.