I Recently Went On A Trip With Some Friends To

I recently went on a trip with some friends to big bear in the mountains . I really got sick and got stomach issues i think we ate something that might of upset our stomachs but only made us really gassy and bloated and it wouldn't go away . Its been 6 months already, and i still have issues with this same symptoms. Everything i eat makes me bloated and gassy. I will eat a salad or fruit and that will still make me gassy. It is so frustrating i don't know if this is something serious. Feel like a parasite went into my body making me feel this way. I have tried detox teas and cleanses to see if that helped and that still didn't help. Some of my friends have the same issue as well ever since this trip. Please advise