Runny poo - could it be teething?

Hiya - I guess I'm just looking for some reassurance here.
I heard somewhere that runny poo can be a sign of impending teething in an otherwise healthy baby...?
DD is fully breastfed and has developed very watery poo in the last few days. It's been pretty hot here too so I'm being extra vigilant about fluids. She's drinking heaps of milk and even started taking water from a sippy cup (as a fun thing she wanted to do - not as a supplement to milk - but she's taken to it with gusto !), and seems well in every other respect (wet nappies, no dehydration signs) so could it just be teething? She's 4.5 months old and chewing everything in sight too.....

Could be. My DS's poos were always different when he was teething (look, smell, consistency). They were pretty acidic and would be the only time I needed to use barrier creams.