<prompt> A 5 year old child with gas under diaphragm is seen in ?Enteric fever with intestinal perforationChilaiditis syndromeIatrogenic pneumoperitoneumAll of the above  <response>: Pneumoperitoneum:free air under the diaphram on an upright chest film suggests the presence of a bowel perforation and underlying peritonits. Enteric fever with intestinal perforation:seen in 1-3 cases,occur in 3rd- 4th week of illness due to hyperplasia,ulceration and necrosis at the ileocecal peyer;s patches at the initial site of salmonella infiltration. Ref : HARRISON;S PRINCIPLES OF INTERNAL MEDICINE,18 TH EDITIONpg no:2692 