i ate a burger 3 days ago at a pub. The next day, i had symptoms of nausea, bloating, an uneasy/heavy feeling in my stomach and I get even more nauseous at the scent of certain foods. I typically have a bowel movement everyday yet, over the course of 3 days, I've only experienced one bout of diahrrea that was light green/grey. Every time I eat, I get very nauseous making it unbearable to eat the rest of the day.Could it be a parasite?