UCN and irritable bowel syndrome: Stress increases gastrointestinal (GI) tract permeability and modifies gut microbiota to promote the pathophysiology of IBD through corticotropin-releasing factor (CRF) and urocortin;47,52–54 these neuromediators then act on G-protein coupled CRF1 and CFR2 receptors in the brain and GI tract53.