In this study, we examined the following biochemical and histological parameters to assess the effects of radon inhalation on DSS-induced colitis: myeloperoxidase (MPO), nitric oxide (NO), tumor necrosis factor-alpha (TNF-α), SOD, CAT, total glutathione (tGSH), lipid peroxide (LPO) level, and histology. Here, TNF is linked to colitis.