Transient receptor potential vanilloid 1(TRPV1) is a nonselective cation channel with high permeability for Ca(2+). It may play a role in the development and maintenance of visceral pain and hypersensitivity states, which has generated a major interest in the development of specific vanilloid antagonists. In this review, a summary of the contribution of TRPV1 in the development of visceral hypersensitivity in functional dyspepsia and irritable bowel syndrome is presented with the structure, location, and related molecular mechanisms.