Dunn’s posttest showed that the PYY cell density was significantly higher in IBS-total and IBS-C patients than in the control subjects (P < 0.02 and P < 0.01, respectively), while it did not differ significantly between IBS-D and IBS-M patients and the control subjects (P = 0.2 and P = 0.5, respectively). Here, PYY is linked to irritable bowel syndrome.