Idiom: Cast Iron Stomach Posted on 15th February 201814th February 2018 by DoubleClick Cast Iron Stomach: be able to eat or drink anything without any problems Example: He thought John must have a cast iron stomach when he saw him eating the spicy Korean food. Share this:Click to share on Twitter (Opens in new window)Click to share on Facebook (Opens in new window) Related Posted in Idiom and tagged Idiom C.