I have been drinking a protein shake every morning for 3 years and just recently I've been experiencing a really bad upset stomach....like a knot in my upper stomach area. If you have never been allegic to any foods, can you develop a food allegy in your 50's? Both my parents are allergic to soy products and this protein shake has a great deal of soy. Could this be my culprit?
Optional Information:
Female , Age: 52
Already Tried:
pepto
other antiacids