GNB3 and irritable bowel syndrome: As showed in Figure 1, eleven studies involving 1,422 cases and 2,073 controls were ultimately included in the present meta-analysis, and eight of them [10, 12, 24, 25, 27–30] specifically investigated the association between GNβ3 C825T polymorphism and different IBS subtypes (including the IBS-C, IBS-D and IBS-M) risk.