We had previously reported that the protective effect of taurine against indomethacin-induced gastric mucosal injury was due to its antioxidant effects, which inhibited lipid peroxidation and neutrophil activation. In this study, we examined the effect of taurine on reducing the inflammatory parameters of trintrobenzene sulfonic acid (TNBS)-induced inflammatory bowel disease (IBD) in rats. In order to induce IBD, ethanolic TNBS was given to rats intracolonically. Then they received 500 mg/kg.day of taurine orally and were sacrificed one week after IBD induction. While ulceration and inflammation of distal colon with formation of granuloma in the vehicle-treated IBD rats two days after administration of TNBS were observed, treatment with taurine ameliorated colonic damage and decreased the incidence of diarrhea and adhesion. also, colon weight as an index of tissue edema, which was mardedly increased in the IBD rats, became significantly lower after administration of TNBS were observed, treatment with taurine ameliorated colonic damage and decreased the incidence of diarrhea and adhesion. Also colon weitht as an index of tissue edema, which was markedly increased in the IBD rats, became significantly lower after taruine treatment. Myeloperoxidase (MPO) activity in the vehicle-treated IBD rats was substantially increased, compared with that of normal control. the taurine-treated animals significantly reduced MPO activity (35% lower) when compared with that of the vehicle-treated animals. Taurine treatment decreased both basal and formyl-methionyl leucyl phenylalanine-stimulated reactive oxygen generation from colonic tissue in the IBD rats. These results suggest that the administration of taurine reduce the inflammatory parameters in this IBD rat model by increasing defending capacity against oxidative damage.