TNF and irritable bowel syndrome: Comparison of cytokines levels in fecal samples at baseline revealed that IL-6 (p < 0.001), IFN-γ (12 times higher) (p < 0.001), TNF-α (p > 0.05), and IL-10 (22 times higher) (p > 0.05) levels considerably varied between healthy individuals and patients with IBS.