Dextran sulfate sodium salt (MW 36,000–50,000) is a medium molecular weight polyanionic dextran derivative with strong intestinal epithelial permeability. It is the most commonly used agent for inducing inflammatory bowel disease (IBD) models, effectively inducing both acute and chronic colitis. Its mechanism may involve macrophage dysfunction and gut microbiota dysbiosis. Due to its colonic epithelial toxicity, long-term use can also induce colorectal cancer models.