Then the droppings are probably all white because the food he recently started eating hasn't made it through his system yet. Give him a few more days of steady eating and you should start seeing a good mix of feces and urates.

I would take a fecal to the vet just to ensure that there are no parasites.

Sounds like he's doing just fine though. It's very normal for a tort to go off feed for a week or more when it has just been placed in a new home. It's a very stressful situation and all they probably care about at that point is finding a nice dark space to crawl into and hide until they feel more confident in their surroundings. A lot of people make the mistake of handling their tort while it's adjusting (either to place it near a food dish or to give it a soak). For the most part, that will actually keep the tort from coming out of hiding for a little bit a longer.