TNF and irritable bowel syndrome: Eight studies involving 1868 IBS patients and 1462 controls were analyzed for the association of TNFα rs1800629 (G > A), four studies involving 470 IBS patients and 485 controls were analyzed for the association of IL10 rs1800871 (T > C), four studies involving 724 IBS patients and 839 controls that analyzed the association of GNβ3 rs5443 (C > T) and IBS risk (Table 1).