Corn may not have gluten but unless you have tested positive for Celiac, and think you might be intolerant, corn can be a culprit of gastric distress. Which is a shame since it tastes so good and comes in so many forms. (corn chips, corn wraps, corn on the cob, polenta...) The good news is that if you figure out what your trouble stems from, it can usually be fixed and then eating wheat, corn, rye, etc. do not have to cause you any trouble.
In the meantime...brown rice farina makes a wonderful creamy cereal that cooks up quickly. Use it for any meal just as you would grits or polenta.
I buy mine here: http://www.vitacost.com/bobs-red-mill-organic-creamy-brown-rice-farina-cereal
It cooks up ultra fast and can be the exact consistency you enjoy by adding more or less water. This afternoon for my lunch it was quite nicely dense and could be as a base for a meal or put right into a soup or eaten out of a bowl with a little flax oil or earth balance on top. (how I always eat it but I do have visions of making a chunky sauce similar to a marinara without the tomato and pouring that on top.