POMC and irritable bowel syndrome: It was proved that the stress was associated with the development of IBS through stimulating the hypothalamic-pituitary-adrenal (HPA) axis and triggering the release of some substances including corticotrophin-releasing factor (CRF), adreno-cortico-tropic-hormone (ACTH), and cortisol, which affect gut function through the composition and the growth of microbiota, and stimulate the sympathetic nervous system (SNS) (75).