Fig 1. Neuroendocrine response models during 40 mmHg distention.

(A) HCs injected with saline (n = 16), (B) HCs injected with CRH (n = 16), (C) patients with IBS injected with saline (n = 16), and (D) patients with IBS injected with CRH (n = 16). *P < .0125 indicate significant paths. The squared multiple correlations (R²) of the variables are reported in the top right corner. There were no significant factor correlations between ACTH and NA. ACTH, plasma ACTH; cortisol, serum cortisol; HCs, healthy controls; NA, plasma noradrenaline; Ad, plasma adrenaline; ACTH, adrenocorticotropic hormone; IBS, irritable bowel syndrome; CRH, corticotropin-releasing hormone.