Acute Ulcerative Colitis (UC) models are established by oral administration of Dextran Sulfate Sodium (DSS) solution. The animals exhibit reduced food intake,weight loss, and fecal occult blood, and the severity of disease is assessed using Disease Activity Index (DAl) scoring.

Inflammatory cytokines in peripheral blood(TNF-a, IL-10,IL-6) are elevated.

Colonoscopy reveals ulcerative lesions, which are evaluated using the UCElS scoring system, while stool characteristics are assessed using the Bristol Fecal Scoring system.

Fiqure 1.Colonoscopy images show fibrin covering the surface of the ulcers in the model animals, with raised edges and blurred vascular patterns.