Cat food that can help bulk up/harden cat's poop?

* I asked this in the cat section and not one reply. I know the dog section is more popular and people in this section tend to also be knowledgeable in cats, so I figured I'd try here next.

I have had my cat on purina for awhile now and he has been having issues with the consistency of his stool. It isn't diarrhea, it's pudding-ish. He goes daily and his poop just isn't well formed, it's just like a plop. He is healthy, no signs of dehydration or watery stool or changes in activity/eating habits. He just needs a change in his food to help form his stool better. So today I switched him to blue buffalo "mature" cat food (dry). It doesn't have fillers, by products and it has omega 3 and 6 which I read is supposed to help with irritable bowel. Do you think this food will help? Or is there another food or remedy you recommend to bulk up his stool?