Hii I wil try to help you in this ,having metallic taste maynot be an appendicitis untill an unless you have fever weakness .But yes if you are having some foid poisoining sort of thing then probably the metallic taste is because of that . Even a simple GERD that is nothing but a reflux disease can also produce metallic taste .All that you need to do is avoid spicy food ,specially in the night ,try to consider a antacid at least for couple of weeks with diet modification .. hope this information will help you .. thank you..