Introduction: Recent neuroimaging studies have suggested changes in composition of brain grey and white matter in patients with inflammatory bowel disease (IBD). In particular, regional cortical thickening has been reported in patients with ulcerative colitis and white matter abnormalities have been reported in patients with Crohn's disease compared to agematched controls. The full range of brain abnormalities in IBD patients and the associated cognitive and affective impairments, however, remain poorly characterized. Here we report preliminary findings from an ongoing study investigating brain cortical thickness changes in patients with Crohn's disease compared to age-matched healthy controls and its relationship with behavior. Methods: Adult patients with Crohn's disease in remission as defined by a Harvey-Bradshaw of 3 or below were recruited from the IBD clinic at the University of Wisconsin School of Medicine and Public Health. Patients with co-morbid chronic pain disorders, taking scheduled medications for pain control, or with contraindications to MRI were excluded. On a 3T MRI scanner, high-resolution T1 weighted structural images were obtained from all subjects and surface based regional cortical thickness measurements were generated using FreeSurfer. Letter fluency task was performed outside the scanner. Four patients with Crohn's disease (age range 20-63 yrs, mean = 38, 2 males) were compared to 7 age-matched healthy controls (age range 22-61 yrs, mean=40, 2 males). All subjects' cortical thickness and performance on the letter fluency task were analyzed.We also examined correlation between cortical thickness and performance on the letter fluency task. Results: We found a statistically significant difference between patients and controls in cortical thickness in the cingulate (p < 0.05, corrected for multiple comparisons) and postcentral (p < 0.005, uncorrected) regions. Furthermore, cortical thickening in the cingulate region correlated with behavioral performance on the letter fluency task (Spearman's rho, p=0.05) in patients. Conclusions: Given that the cingulate region is heavily implicated in various processes such as attention, executive function, and emotional processing, these early findings suggest that patients with Crohn's disease may undergo structural brain changes that may be associated with clinically relevant behaviors. Further investigations of such changes using advanced neuroimaging techniques will likely improve our understanding of brain-gut interactions in patients with IBD and may reveal mechanisms by which observed impairments in cognitive performance and emotional processing develop in this population.