The subject invention pertains to materials and methods for the prevention and treatment of disease conditions associated with oxidative stress or a compromised reducing environment, including inflammatory bowel diseases such as Crohn's disease and ulcerative colitis. Therapeutic compositions of the invention include compositions that can neutralize hydrogen peroxide, such as reducing agents and oxidizing agents. In one embodiment, a composition includes dihydrolipoic acid as a first reducing agent, an aminosalicylic acid, and a mast cell stabilizer. In another embodiment, the composition further includes a second reducing agent. Methods of the invention include administration of compounds or compositions of the invention. In one embodiment, compounds or compositions of the invention are rectally instilled in a patient.