X-ray of the stomach with both positive (bariumsulphate) and negative (CO2)contrastmedia.
<a href="//commons.wikimedia.org/wiki/User:Lucien_Monfils" title="User:Lucien Monfils">Lucien Monfils</a>
CC BY-SA 3.0
<span class="int-own-work" lang="en">Own work</span>