The limited efficacy of standard medical therapies for inflammatory bowel diseases has resulted in a continuing search for alternative treatments. Growth hormone (GH) has shown to have mutagenic and proliferative effects on intestinal cells. This study was designed to identify the effect of growth hormone on trinitrobenzene slfonic acid-induced colitis (TNBSIC) in rats. This study was carried out on 30 rats, divided in 3 groups: group 1: TNBSIC+ GH, group 2: TNBSIC, group 3: saline enema. Colitis was induced in male Sprague-Dawley rats (200 g-250 g) by intracolonic installation of 2, 4, 6-trinitrobenzene sulphonic acid in 50% ethanol. GH treatment has been started and continued throughout the study after inducing colitis. All rats were killed after 5 weeks and colonic segments were examined histopathologically. Microscopic and macroscopic damage scores were caulculated. Intestinal damage scores were found higher in Goups II when compared with treatment group (P < 0.05). There was no damage in group 3 as expected. Both macroscopic and microscopic scores were highest in group 2 (P < 0.05). The myloperoxidase activity was found lower comparing to group 2 (P < 0.05). In conclusion, growth hormone replacement had protective effects against colonic inflammation while reducing intestinal damage on TNB-induced colitis.