Corn can show up in a person's stool as soon as a few hours after consuming it, states PoopReport.com. Generally speaking, food is fully digested, passes through the intestine and out of the body in the form of stool, within 18 to 24 hours, explains Colon Hydrotherapy.
When corn passes through the digestive tract it often comes out in what appears to be its fully intact state. Although corn in stool may look whole, the body has removed the nutrients from it, reports Science Focus. The inside of corn is made up of starch, which is easily digested by the body. The outside is a layer of cellulose, which, unless chewed very thoroughly, is not easily digested.