So having rotten egg burbs for more than 12 hrs would be a bad thing?

Rotten egg burps: If your burp smells like rotten eggs if may be due to release of hydrogen sulfide (H2S).This could happen more often in pregnancy, with irritable bowel syndrome, GERD or other conditions. For 12 hours only - wouldn't really sweat it. Take care.

Not really.: Rotten egg burps mean you have eaten something with a lot of sulfur in it. Your bacteria have broken that food down and what you smell is the sultur. Sulfur-rich foods include garlic, onions, eggs, or even red wine. Think about what you have eaten over the last day. Then don't eat whatever it was for the next 24-hours. Your smelly burps will probably go away!