This study is supported by findings that Irritable Bowel Syndrome patients have an alteration of the hypothalamus-pituitary-adrenal stress axis such that cortisol levels are elevated. Stress-induced release of corticotropin-releasing factor alters gastric digestion and gastrointestinal motility. Furthermore, stress is a contributing factor to the immune activation and low-grade inflammation observed in Irritable Bowel Syndrome with overall physical and psychological distress correlating with percentage of activated natural killer and T cells. In addition, the brain-gut axis is a proposed mechanism in Irritable Bowel Syndrome due to dysregulated enteric nervous system and central nervous system events. The central nervous system may perceive visceral stimuli from the gut mucosa when inflammation or injury causes afferent nerve sensitization.