Say if you lived 18 years with horrific gas, and then…they suddenly stop smelling it has continued to do so for the last 10 years, what would cause such a thing?
No changes in diet. No more or no less episodes of flatulence per day than usual.
The stuff in their guts (enzymes/bacteria) that made the foul smell were eaten by bigger/meaner organisms that don’t produce the same odor?
Olfactory nerve damage?
Yeah, you finally burned your nose out?
Rather like the old joke: A aged couple are sitting in church. The wife whispers to her husband, “I just passed gas silently. What should I do?” The husband says, “You should change the batteries in your hearing aid.”
Charcoal underpants.
Flower diet?