Establishment of Post-Inflammatory Irritable Bowel Syndrome Animal Model Following Acute Colitis Recovery

Irritable bowel syndrome (IBS) is a prevalent disorder with an unclear pathophysiology. This study aimed to establish an experimental murine model of post-inflammatory IBS induced by acute severe colitis (acute model) or chronic mild repeated colitis (chronic model) to facilitate IBS analysis. The acute model was induced with 3% dextran sulfate sodium (DSS) for 5 days, followed by a 12-week recovery period. The chronic model involved administration of 0.5% DSS for 5 days, followed by a 5-day resting period, repeated thrice. We conducted comparative analyses to assess inflammation severity, intestinal motility, permeability, visceral hypersensitivity, and microbiome composition. In the acute model, mild leukocyte infiltration was observed, colonic transit time shortened at 12 weeks ( P  < 0.001), occludin expression decreased ( P  = 0.041), and inflammatory cytokines and transient receptor potential vanilloid 1 was upregulated in colonic mucosa ( P  < 0.050). In the chronic model, only mild inflammatory changes were noted. Microbiota analysis in the acute model revealed differences in microbial abundance and compositions ( P  = 0.001). The acute model effectively induced a post-inflammatory IBS model, characterized by low-grade inflammation that causes gut dysmotility, alters permeability, and increases visceral hypersensitivity with notable microbial composition changes.