Left lateral decubitus AXR (above left) shows an air filled duodenal bulb and an air filled stomach (double bubble sign) with some distal bowel gas. Transverse US of the pylorus (below left) shows from left to right a fluid filled duodenal bulb, normal pylorus, and fluid filled stomach (double bubble sign). AP image from an upper GI exam (below right) shows a distended stomach and duodenal bulb with the remainder of the duodenal C-loop having a normal caliber.