Irritable bowel syndrome (IBS) is a common functional gastrointestinal disorder characterized by recurrent abdominal pain and altered bowel habits, and in a subset of patients, by a compromised colonic epithelial barrier function. IBS predominantly affects women, but the underlying mechanisms of this female prevalence remain largely unknown. Stress is known to worsen IBS symptoms. In male rodents, chronic stress increases colonic secretion and paracellular permeability, the latter being associated with visceral hyperalgesia. Potential sex differences in the colonic epithelial response to stress have not yet been addressed. In this study, the effect of stress on colonic mucosal function was determined in male and female Wistar and Wistar-Kyoto rats (7-11 wks, n=4-8/group). Naïve or stressed (repeated water avoidance stress or rWAS, 1h/day, 4 days) rats were euthanized 5h after the last stress session. Proximal colon (PC) and distal colon (DC) were collected, stripped from the seromuscular layer and the mucosa was mounted in Ussing chambers containing modified oxygenated Krebs Ringer’s buffer. The conductance (G) and short circuit current (Isc) were measured. Data were analyzed using unpaired t test. In the PC of both Wistar and Wistar-Kyoto females, rWAS increased the Isc (75.9±10.0 vs 26.3±2.1 & 57.6±3.8 vs 38.4±3.3 μA/cm2, p<0.01, respectively) while it did not affect the Isc in male rats. In the DC, both male and female Wistar rats displayed an increase in Isc following rWAS (79.4±11.5 vs 28.7±2.5 and 79.0±10.2 vs 20.8±1.9 μA/cm2, p<0.001, respectively), while female Wistar-Kyoto rats showed a decreased Isc (34.6 ± 3.8 vs 51.1 ± 5.7 μA/cm2, p<0.05) and males no change. Females, but not males of both strains exhibited an increase in G exclusively in the PC following rWAS. In conclusion, our results show that female rats exhibit an increased susceptibility to develop colonic epithelial disturbances during repeated psychological stress which is conserved among different strains. This altered colonic response may contribute to the greater prevalence of visceral hypersensitivity and IBS symptoms in women.