What gastro tests did you have done? Also, do you think this thing could just be leaky gas. It doesn't make sense though for one, that egg smell is not in my urine, crap, or when I actually do pass gas. Two it happens at certain random times and just keeps happening (like when I'm in public) then stops or is not as bad when I leave. Three there's no gas in my stomach when it happens. So leaky gas doesn't make sense to me. Some people are saying it could be like hemorrhoids or like weak anal sphincter. I've had a hydrogen breath test, it was fine says doctor, I've had upper endoscopy, and colonoscopy, doctor said they were fine, I've had two stool tests, doctor said was were fine, I had blood work to check thyroid, fine, blood work to check for allergies, fine, urinalysis (just constant white blood cells) and no uti, so like I was saying I've had like every gastro test. Plus, I took antiparasitics and herb supplements. Still random smell sometimes.Not the egg one lately, but this one is like flatulence. I was also thinking if there was something wrong with gas leaking out he would have probably noticed during colonoscopy so no need for rectal surgeon. Let see, have you checked anything with bladder, kidneys, liver. I'm starting to wonder if it has to do with that. Either that or metabolic issue, but your saying you saw a metabolic specialist. Did you get tested for type 2 TMAU. There has to be a logical reason for this.