The putamen has shown decreased gray matter volume in chronic pelvic pain [4] and IBS [43]. The thalamic region that showed decreased FA in IBS is associated with projections to the anterior cingulate and prefrontal cortices, however, in contrast to the thalamus, the FA in the prefrontal cortex is higher in IBS, as are the number of tracts connecting the thalamus to the prefrontal cortex.