My two brother kittens have a ravenous appetite and thirst. They get fed Purina Signature Solutions blue flavor twice daily. Three times daily their water dish is refilled due to being empty.

Their bellies are always full and puffed out.

Recently one or both have been puking. Not more than once or twice a day and it does not seem to be immediately after feeding.

I do not take them to the vet - a friend who is a pre-veternarian undergrad student said she saw a worm in one's butt. We have never seen any evidence to indicate that she is right.

However if the puking is related to the possible worms, I am eager to do something to fix it (other than the vet)
Thanks for your help.