Tu1799 Differences in Cortisol Responses to Hormone Challenge vs. Visceral Stressor in Irritable Bowel Syndrome

stress was higher in IBS vs controls (28±5 vs. 25±6, p=0.003) and in IBS-D vs. the other IBS subtypes (p=0.040).The number of tryptase-positive cells was significantly increased in IBS vs controls (380±181 vs. 243±95/µm, p=0.001) and tended to correlated with stress in IBS (r: 0.30, p=0.056) but not in controls (r: -0.08, p=0.332).In addition, perceived stress explained 9.4% of the variation of tryptase + mast cells.Conclusions:Rome II-IBS patients from a low socieconomical level in Mexico showed an increase in rectal-mucosal tryptase-positive mast cells which correlated moderately with perceived stress.The latter central effect explained small variations in the mucosal degranulated mast cells, thus treatment of stress in IBS may decrease mast cell degranulation and symptoms could improve.