Serial sections were taken from ten percent formalin fixed paraffin embedded tissue blocks of intestinal tissues and stained with Hematoxilen & Eosin (H&E). Tissue injury in the intestinal mucosa was evaluated using light microscopy according to the criteria described by Chiu et al. and graded from 0 to 5. The grades are: Grade 0: Normal mucosa; Grade 1: Formation of subepithelial detachments at the tip of the villi with capillary congestion; Grade 2: Subepithelial detachments exerted a moderate amount of upward push on the mucosa epithelium; Grade 3: Large subepithelial detachments exerted a massive amount of upward push on the mucosa epithelium along the villi and few denuded villus tips were observed; Grade 4: The villi were denuded to the level of lamina propria and dilated capillaries; Grade 5: Presence of ulceration, disintegration of lamina propria, and hemorrhage.