Peas are actually for goldfish, somehow someone said they'd work for bettas. Bettas can't actually digest peas, so it generally isn't very good for them. It can work if you have no other options--but I wouldn't suggest it! I don't know about sugar snap peas, though!
If you can get daphnia, that's much better for fixing up SBD, and get the fish in QT with some epsom salt and indian almond leaves(or clean oak leaves)
Peas aren't a good thing.. Please don't kill your betta by giving him peas.. peas are for constipation and bloating in a goldfish.. SBD is something completely different. IF he even eats it, you will make matters worse as they can't digest it and your putting something in him when you need to be taking things out. Especially putting in something that can't be digested and can potentially harm him. You should fast him for 1-2 days.. as well as change his diet. What is he feeding them and how much? Only reason I ask is to prevent this from happening again.
What symptoms is he having?
Go to Walmart, or any pharmacy and get Epsom Salt (unfragranced, regular). You can get a big container of it at Walmart for less then $2.
1-2 teaspoons of it per gallon (dissolved prior to putting it with the fish, also add in water conditioner), daily 100% water change for 3 days past the last time you see symptoms.
Honestly I agree, I know I said it will work, what I meant is I have seen people use it supposedly with success, but they also fasted their fish during the time, and honestly it was probably the fast that cured the fish!
See if the fasting helps him. :D Just let him get anything cleared out of his system. The epsom salt can help with him too, and you get so much for so cheap, that the rest of the bag is still free for anything you or your family could want. Good for people in a lot of different ways(as scrubs, relaxers, even to heal bruises and stuff! Useful little bag of salt!)
well, I might just fast him, because I won't see him for a week starting tomorrow, I am only at my parents house saturday nights to sundays... will he be ok? i hope so... he is starting to go more sideways now...
Unfortunately, it sounds like he needs help now.. lower his water to 3-4 inches so he can reach the surface easier. You can get the salt and maybe write down the instructions to your parents so they can treat him while you are away?