IL4 and fibrosis: (1) Reduce body weight loss and mortality rate, and restore colon length; (2) Repair colonic mucosal damage and reduce inflammatory cell infiltration; (3) Simultaneously decrease MDA and MPO levels, while restoring SOD and CAT activity; (4) Reduce pro-inflammatory factors such as TNF-α and IL-1β, upregulate anti-inflammatory factors such as IL-4 and IL-10, and suppress the expression of intestinal fibrosis-related TGF-β; (5) Increase goblet cell count and mucus secretion, and repair the intestinal epithelial barrier