No air under diaphragm on erect chest radiograph.
AP supine abdominal radiograph.
- Grossly dilated large bowel loops. Reminiscent of "Coffee bean sign" at left side of abdomen.
- Frimann-Dahl sign - three dense lines (sigmoid walls) converging to the pelvic region/site of obstruction with empty rectal gas.
- Absence of rectal gas.