Depends on what you're adding back...and how much.

Some LCers find that they actually don't digest wheat or other high-gluten grains very well...and they likely never did but when they ate a lot of carbs and were overweight, they just didn't notice! It's a case of, "I didn't know I felt bad until I found out what feeling good is like."

So try adding back higher-carb veggies first, then fruits, then only one grain at a time....maybe brown rice which is low-gluten. Try one grain per week and you may find which one is bothering you. Rice one week; wheat the next; and so on. Besides, you may just find that you can get through life very happily without wheat altogether.