One hypothesis suggests an overactivation of the hypothalamic–pituitary–adrenal (HPA) axis, evidenced by elevated cortisol levels due to increased adrenocorticotropic hormone (ACTH) release from the pituitary gland in individuals with IBS, potentially secondary to elevated corticotropin-releasing factor (CRF) levels [11]. This evidence concerns the gene POMC and irritable bowel syndrome.