just amoxicillin, or co-amoxiclav ?
how much are you taking and how long have you been on it ? How long left ?
did you have no diarrhoes before starting the amox ?
(presumably no BBQ recently ?)
Amoxicillin doesn’t cause irritant diarrhoea that often, though possible (and is typically a dose-related thing). It can – especially after multiple other courses of abx (even just metronidazole) – predispose to overgrowth in the gut of something called C.difficile, which can cause fairly severe diarrhoea/colitis. It’s not top of the “risk list” for that (and nor is metronidazole) but is possible. If you fancied, yr GP might well be interested in sending a sample of yr poo for testing (I’m guessing that dentists can’t request this)
If they don’t find C.diff toxins in your puddle, it’s also possible that “just” disruption of the bacterial microbiome in yr gut is causing the splats and the hope would be that this would reset fairly quickly after stopping