Mesenchymal stem cells (MSCs) have recently gained popularity as a treatment for a variety of diseases. In this work, bone marrow MSCs (BM-MSCs) and adipose MSCs (AD-MSCs) were compared to dexamethasone (Dex) in the management of colitis induced by acetic acid in rats. Rats were divided in a random way into five groups: (1) Control, (2) Acetic acid treated (2 ml of 3% of acetic acid solution, intra-rectally as a single dose), (3) BM-MSCs treated (single i.p. administration of 1×106cells/rat, 24 hours after acetic acid exposure), (4) AD-MSCs treated (single i.p. administration of 1×106 cells/ rat, 24 hours after acetic acid exposure), and (5) Dex treated (0.5 mg/kg/, i.p., 1 hour after acetic acid exposure) for 7 days. Following that, after 15 days of colitis induction, all rats were decapitated. Acetic acid induced colitis was marked by elevation of edema marker, myeloperoxidase, malondialdehyde, interleukin-1β, tumor necrosis factor-alpha, interleukin-6 apoptosis via caspase-3 expression, fibrosis using Masson's trichrome stain as well as infiltration of inflammatory cells by means of hematoxylin and eosin stain, It also lowered superoxide dismutase, total antioxidant, and interleukin-10 levels. After receiving either BM-MSCs or AD-MSCs, these adverse consequences were dramatically reduced. Finally, anti-oxidant, anti-inflammatory, anti-apoptotic, and anti-fibrotic activities were detected in AD-MSCs BM-MSCs and, indicating that they could be promising novel therapeutics for the treatment of colitis.