There are no differences in the IBS subtypes; however, in IBS‐C, malondialdehyde correlated with IL‐4, and TNF‐α with IL‐10, suggesting an interleukin‐mediated anti low‐grade inflammation mechanism, and in IBS‐D, GSH correlated with IL‐4, suggesting an antioxidant mechanism. This evidence concerns the gene IL4 and irritable bowel syndrome.