TNF and irritable bowel syndrome: Pathophysiologically, IBD is complex as it involves the interaction between four components: an aberrant immune system, genetic factors, environmental factors, and the intestinal microbiota that result in chronic inflammation. The inflammatory response is mainly mediated by T-helper 1 and T-helper 17 cells in the case of Chron's disease and T-helper 2 in the case of ulcerative colitis, in addition to cytokines such as tumor necrosis factor-α (TNF-α), transforming growth factor-β, interleukines, reactive oxygen species (ROS), neuropeptides and non-immune cells [12].