Have you discussed further diagnostic work for the liver? If it isn't functioning as it should then diarrhoea can be a consequence of that. So although it's the obvious thing to focus on, it's important to find out if possible what is causing it. Sometimes to find out what that is involves quite invasive procedures, which you may decide not to do. If that's the case, you will have to try some symptomatic therapy as you are doing. This new episode of diarrhoea could be incidental to the main problem, but as long as Dusty is happy with a good appetite there's no reason to worry immediately. When you return to your vet for a check-up, ask about the possibility of further work, but give this current episode a chance to resolve first.