Your dog is on revolution you saw a flat worm in his stool Is there another med for that?

The description sounds like a tapeworm. Yes, there is a different medication to treat them (a form of dewormer that your vet will be able to provide). Treatment should be easy after obtaining proper medication for your dog.

Revolution is a monthly preventitive that treats against fleas and heartworms and some other types of parasites such as ticks, ear mites, and sarcoptic mange.

Good luck!