Axial and coronal CT images following intravenous and oral contrast administration show diffuse colonic wall thickening with mucosal enhancement involving the caecum, ascending colon, transverse colon and proximal descending colon. Hyperaemia can be appreciated with prominence of the pericolonic mesenteric vessels. Mild pericolic fat stranding is present. Faecal sample obtained for culture was positive for E. coli (0157:H7).