I occasionally feed my Bettas a little frozen brine shrimp and today my boy Flare got a bit bloated again. Should I fast him tomorrow? I don't know why sometimes they get bloated all of a sudden even if I don't change their diet. I don't give them a lot. I've also been giving them occasional peas once a week or so.. thanks..

Fasting cant hurt, I always fast mine one day a week.

I take it youre defrosting the brine shrimp first? just checking.
Try daphnia as that has a laxative effect but you can only give bettas very small amounts of food.