School ager with abdominal pain, diarrhea, and vomiting

AXR and CT and US of pseudomembranous colitis
AXR AP (above left) shows thickening of the haustra of the transverse colon (thumb printing). Axial CT with contrast of the abdomen (above right) shows diffuse thickening of the colon which is markedly thickened in the ascending colon compared to the descending colon. An accordion sign is demonstrated in the ascending colon. Sagittal (below left) and transverse (below right) US of the cecum show a diffusely thickened cecum.

The diagnosis was pseudomembranous colitis.