I recently experienced the same symptoms (bloating, belching, diarrhea, nausea, vomiting) as was related in the previous posting. My doctor attributed it to a virus in the stomach possibly created from eating a not-so-fresh food item. I took an antibiotic to relieve the nausea and vomiting sensations and Petmo Bismal for the other symptoms while eating a BRAT diet and drinking much liquids. Symptoms have lessened but not 100% on the fourth day. It is difficult to diagnose the cause, perhaps it can be due to diet for some while perhaps it may be a medical problem for others. May the Lord give us a cure for the illnesses we encounter.
I too have had those gross eggy burps, severe cramping and bloating that's left me in bed for a day and feeling like garbage for a week. I have Crohn's Disease, so I thought it was due to it. After numerous gastroenterological tests and allergist tests, it turned out I have a lactose, egg AND fructose allergy/intolerance. Weird for me because I was never allergic to anything a day in my life. In the past, I've eaten things with them and never had a reaction. Once I stayed away from things with those ingredients in them, everything stopped. If anyone tried to sneak any of those things in food or is unaware of my allergy and used those types of ingredients, the debilitating pain, severe bloating and eggy burps would begin again.
Btw, this didn't happen to me all at once. It was gradual through the months. It started out as a slight discomfort, then a little more than slight, followed by mild diarrhea, then a lot more than slight cramping, moderate diarrhea and mild bloating, to severe in all 3 categories, especially the bloating where I had to wear very loose sweatpants because the pressure of my regular clothes on my stomach was excruciating, but throughout all those stages, that disgusting eggy burp has always been the same. I always felt it was perhaps something I ate that was rotted away in my intestines and now I have to suffer the consequences of the lack of digestion.
I don't know if my experience will help, but I thought I'd share so you can see if this is happening to you. A GI will not be able to diagnose this, even though all the problems are gastrointestinal. Request to see an allergist or request an allergy test for an allergy or intolerance.