Also, there were no significant differences between the levels of IL-12 and IL-4 in the intestinal mucosa in the PI-IBS (0.14 ± 0.01 of IL-12 and 0.23 ± 0.02 of IL-4), non-PI-IBS (0.12 ± 0.01 of IL-12 and 0.21 ± 0.02 of IL-4), and control groups (0.13 ± 0.01 of IL-12 and 0.24 ± 0.02 of IL-4) (both P > 0.05). Here, IL4 is linked to irritable bowel syndrome.