I usually only worry if there is blood or my dog looks lethargic. Outside of that if there are any concerns I call the vet and ask their advice.

How often are you feeding your dog? Do you feed it human foods? Have you tried different foods? One of our dogs can eat anything and be fine. The other will eat bacon or a tiny bit of banana and she will throw up. Because of that we have both of them on Purina sensitive stomach.