First off.........Bless you for choosing to Adopt and not Shop!
when asked how much you feed.............how much is two bowls a day? 2 cups twice a day................or what.
have your Vet check a stool sample?
if all is good..........try adding more fiber to his diet.....pumpkin seems to work well with dogs.
google and research Slippery Elm Bark Powder. an awesome herb for any digestive disorders.
Hope things improve for your boy.