Anything can cause anxiety and stomach pain, it depends on how your body is and what it reacts to. Everyone reacts differently to things, including how people treat them, no one is the same. And metoclopramide still works, people have different genetic makeup, it might work for someone but its not sure what would happen to someone else, while taking the same dosage of the same medication. What you could do is try it, if it doesn't work then theres always other antiemetics.