Severe pain on left side by hip bone had diarrea for a couple of days and gas eating fine just vomited acid like mucus. What could this be?

I'd say it's time to seek the opinion of your doctor or nurse practitioner.

Please be advised that there are no doctors on this site. As to your post, it is very hard to understand for the individual, not only the medical professional. You need to seek medical attention in person, rather than online, to get an accurate diagnosis.