In humans, patients with irritable bowel syndrome (IBS) were found to have increased adrenocorticotropic hormone and cortisol levels in response to corticotropin-releasing hormone infusion and elevated levels of the proinflammatory cytokines IL-6 compared to controls, an observation that suggest over activation of the hypothalamic-pituitary-adrenal axis (86). This evidence concerns the gene POMC and irritable bowel syndrome.