If it were me, I would throw that crap as far as I could away. None of the
Science Diet/ Hills, or for that matter, Iams, Purina,
Beneful, etc., etc. are any good at all. As a matter of fact, they are causing so much harm to our pets that vet visits are at an all time high.
The turkey/pumpkin mixture should right his digestive system fairly quick. If it don't, then he has something else going on.
Once he is over this, get him on a premium food that is grain free.