Portulacaoleraceal (POL) has been widely used as an edible plant and a folk medicine in many countries, due to its several health benefits. This study examined the effects of POL on trinitrobenzene sulfonic acid (TNBS)-induced colitis via enema administration. Sixty male Sprague–Dawley rats were randomly divided into five groups: untreated, TNBS, TNBS + POL 10 g/kg, TNBS + POL 5 g/kg and TNBS + POL 2.5 g/kg groups. Rats were subjected to enema treatment once a day for 10 consecutive days with POL extract or distilled water after induction of TNBS. The changes of body weight, histological parameters, myeloperoxidase (MPO), superoxide dismutase (SOD), nitric oxide synthase activity (NOS), malondialdehyde (MDA) and nitric oxide (NO) levels in colon tissues were investigated. After POL extract treatment, body weights of rats significantly increased, macroscopic and microscopic damage scores reduced, MPO and NOS activity, as well as MDA and NO level significantly decreased, while SOD activity increased in a dose-dependent manner in the TNBS + POL groups compared with the TNBS group. Our results demonstrated that POL enema treatment attenuated pathologic changes of TNBS-induced colitis in rats through restoring colonic damage and reducing inflammatory response in the intestine. Thus, POL enema might be considered as a potential effective treatment for ulcerative colitis patients.