S1PR2 and Hematochezia: The results showed that S1PR2 blockage significantly reduced the body weight loss and colon length shortening (Figures 5(a) and 5(b)), exhibiting much lower MPO activity and hematochezia score (Figures 5(c) and 5(d)), meanwhile ameliorating mucosal inflammatory cell infiltration and mucosal epithelium disruption (Figure 5(f)).