<prompt> Tell your diagnosis:Intestinal obstructionPerforation peritonitisParalytic ileusChiladitis syndrome  <response>: Ans. b Perforation peritonitis Air under diaphragm on the right side indicates a hollow viscus perforation The best imaging for hollow viscus perforation is X -ray abdomen erect The minimum amount of air detected on erect X-ray: 1ML. If patient cannot stand erect due to peritonitis: Left lateral decubitus X-ray is taken. This image will detect 5-10mL of air. Chiladitis Syndrome: Interposition of colonic shadow between the liver and diaphragm appears like perforation air under diaphragm. 