I have a 9 week old puppy, and ever since I took him to the vet to be de wormed and have his shots, he started having runny bloody poop. Its not always like that, sometimes its very normal looking. He is a very happy and energetic puppy and doesn't appear to be in any pain. He just went on our bathroom tile and there was about a teaspoon or so of blood, and hardly any poop. Anyone know what this may be?

He still has worms. Take him back to the vet as soon as possible.