Why is my puppy's poop green, crumbly, smelly, with rice-like bits?

The food change could be causing the color of the stool and the bad smell, but the rice sized things look like tapeworms. Tapeworms required praziquantel to treat, which is prescription only from the vet. You need to tell your friend to take him into the vet in the morning to get this treated. He will also need to be treated for fleas, as fleas carry and transmit tapeworms to dogs. Have her discuss his diet with the vet as well so he can get the best one for him. I hope this helps!