Do allergies to food cause gastritis?

They may: There are many ways to cause distress. First, go see your doctor. Make sure nothing else is causing this. Then try an elimination diet for 30 days, adding foods back one at a time (every 5 days), watch for reactions.You may have outright allergies or food intolerances. Both can cause distress. Meanwhile try dgl (deglycyrrhizinated licorice) before each meal to start to heal the stomach lining.