I wish I knew what it was. I am in the same boat. I have the sulfur burps. Sometimes the vomiting comes first followed by diarrhea quickly after the burps start. Sometimes I have the burps still on the 2nd day then diarrhea starts which is the case today. Other times I only have vomiting follow soon after the burps start. This is happening more frequently as time goes by. I am having a very hard time getting a Dr to run tests to find out the cause. They keep trying to say it's just a stomach virus. None of the prescription nausea meds that I'm not allergic to will work. I don't even want to take anti diarrhea meds to stop it up in my body. I just want it out. I am so frustrated trying to research myself to figure out what it is. Doctors please do your job and help your patients.