I have ulcerative colitis and when I am having a flare up, the advice I am given is to eat LOW RESIDUE food- ie- white pap that is easier and faster to disgest. White bread in this instance is better than brown, as it is less stress on the stomach to digest. As said, acid lives in your stomach- that's where it lives, to digest the food! But you can have too much acid in your diet which can cause problems, or a hiatus hernia which can cause a leaky valve, so the acid comes up above where it should do, especially if you eat too fast or late at night. Look up an alkaline diet and try and eat those foods rather than acidic ones. Don't eat after 8pm and eat slowly. Try to have smaller meals.