Ulcerative colitis (UC) is a type of inflammatory bowel disease (IBD), characterized by chronic inflammation of the gastrointestinal tract. In general, IBD is more common in Western than in Eastern places, and in industrialized than in developing countries. However, the incidence of IBD has been rising recently in Eastern countries including Egypt. Symptoms of IBD include loss of appetite, tenesmus, abdominal cramps, diarrhea, and bloody stools. Available treatment options of IBD include drugs, surgery, or a combination of both. One of the most commonly used drugs for IBD management is an aminosalicylate called sulfasalazine. Several factors and symptoms of UC finally contribute to weight loss; thus, most of UC patients suffer from significant weight loss. The pathophysiology of IBD is complicated and involves several factors including immune, genetic, and environmental factors. Recently, a huge amount of research has concentrated on the role of oxidative stress in IBD, and several studies have proven that IBD patients suffer from excessive amounts of reactive oxygen species, while they have lower than normal amounts of antioxidant defenses. This leads to elevated amounts of oxidative stress-end products like malondialdehyde (MDA). In this study, we investigated body weight loss, histopathological alterations, and MDA levels in a mouse model of dextran sulfate sodium- induced UC, and the therapeutic effect of sulfasalazine. Our results showed that induction of colitis causes significant body weight loss and induces oxidative stress, and that treatment with sulfasalazine could restore normal mice body weights and combat the colitis-induced oxidative stress.