[Help] 9-year-old Maltese's suddenly emitting deadly farts

Edit: just noticed the typo in the title 😖

Wondering 1) what could be causing it and 2) how to stop/lessen it.

Within the last week, my sweet lil doggo has started producing the foulest farts. She has never done this before in her entire life- she has occasionally farted before of course but it was always odorless. These silent but deadly stinkbombs started very suddenly last Tuesday and have continued every day since then. Nothing about her diet has changed. Coincidentally she just had vet annual vet checkup 2 weeks ago and everything was good so I don't think it's some undiagnosed medical condition.