Yes,diarrhea can definatly be brought on by stress. Make sure when you are experieinceing it, either from stress of a gluten attack you drink plenty of fluids, ginger ale, tea,chicken brooth even, not just water, these help to replace the electolytes you lose. Sodium and potassium go first so if you can eat a bananna that would be good.
You can actually lose up to a gallon of water a day with diarrhea.