This is an erect chest xray. In this example there is free gas in both the right and left hemidiaphragms consistent with gastrointestinal perforation, most likely due to peptic ulceration of the stomach or duodenum, or possibly colonic perforation. If perforation is suspected but there is no free gas, which occurs in 40% of cases, a gastrograffin meal would be requested and has a sensitivity of 90% in detecting perforation.