I am an ERr nurse and have battled the problem for quite a few years. I have been taking Aciphex for GERD. After multiple test by GI we tried Align (probiotic) OTC. Prior to the probiotic I was having an episode every 2-3 weeks. It has been 4 months since the last episode.
Giardiasis. It is a parasitic infection of the upper small intestine caused by the organism Giardia lamblia. Often infection causes no symptoms, however it can be responsible for mild to severe diarrhea, abdominal cramping, bulky, greasy, frothy, foul smelling bowel movements and "rotten-egg" burps.
Not sure I'm not a health professional. I just Googled Rotten Egg Burps.