I've come to believe that I have the "stomach bug". On Monday I vomited twice . I ate a fish sandwich around 12noon , threw it up around 4pm. And a piece of brownie around 7, threw it up a half hour later. On Tuesday I had diarrhea. And I threw up again on Wednesday . Now , I got a fever blister , cold sore , whatever it's called, on Monday afternoon , after my first vomit . It's now Saturday , I'm currently cramping , and I still have my fever blister/cold sore. Does the fever blister and stomach bug have any relation ???