<prompt> A large volume of gas is seen at sub diaphragm level in x ray presentation diagnosis isPeritoneal perforationIntestinal obstructionParalytic ileusIntussusception  <response>: A. i.e. Peritoneal perforation 994-B L 25th Radiological Findings Peritoneal perforation Peritonitis - Erect chest x-ray shows free air under the diaphragm perforated viscus Presence of dilated gas-filled loops of bowel or show free gas. Intestinal obstruction - multiple gas-fluid levels are most important criteria, ladder-like pattern Paralytic ileus - shows gas -filled loop of intestine with multiple fluid levels Intussusception - shows an absence of caecal gas shadow and increased gas shadows in the small intestine 