Figures 6, 7. (6) Free intraperitoneal air in a 16-year-old boy who was hit by an automobile. CT scans show a large amount of free intraperitoneal fluid (F), which is not accounted for by parenchymal or osseous pelvic injury. There is slight bowel wall thickening (arrows in a). A tiny bubble of extraluminal gas is seen anteriorly (arrowhead in b). Fluid is seen at the mesenteric root (M in a). Two sites of small bowel perforation and a degloving injury of the sigmoid colon were found at surgery. (7) Free intraperitoneal air in a 6-year-old boy with abdominal pain after a motor vehicle accident. The patient was treated conservatively for 3 days. CT was performed due to increasing pain and new fever. CT scans show free intraperitoneal fluid (F), free intraperitoneal air (arrowheads in a), bowel wall thickening (arrows), and mesenteric stranding (M), which are indicative of bowel perforation with peritonitis.