Table 3.
Brain regions significantly activated by heterotopic stimulation during rectal pain (z score >3, Bonferroni-corrected, two tailed)
| Controls | IBS-C | IBS-D | |
| Cingulate anterior | +Bilateral* | ||
| Cingulate posterior | +Bilateral | +Right†* | |
| Prefrontal cortex inferior | +Bilateral† | +Bilateral† | |
| Prefrontal cortex superior | +Bilateral | +Bilateral | |
| Insula anterior | −Bilateral‡ | −Right | |
| Insula posterior | −Left | ||
| Thalamus lateral | +Bilateral§ | ||
| Thalamus medial | −Right | +Bilateral¶ | |
| Thalamus anterior | +Bilateral§ | ||
| S1 | +Bilateral | ||
| PAG | −Midline | ||
| Orbitofrontal | +Bilateral** | ||
| Amygdala/hippocampus | +Bilateral†† |
IBS, irritable bowel syndrome; IBS-C, IBS with constipation; IBS-D, IBS with diarrhoea; PAG, periaqueductal gray.
+, Significant activation; −, significant deactivation; Bilateral, bilateral symmetrical activation changes; Right or Left, respective asymmetrical activation changes.
*Increased versus IBS-D; †increased versus IBS-D; ‡decreased versus IBS-C and IBS-D; §increased versus healthy and IBS-D; ¶increased versus healthy; **increased versus healthy and IBS-D; ††§§increased versus healthy and IBS-D.