He will be perfectly fine, Most dogs do that, It does take a while to digest but other than that he should be perfect.
Some dogs do that If they aren't getting enough food or they don't like the food they have now, Maybe try a new food. Or wet food mixed with the normal dog food, You can find some at pet smart and other pet stores.
Probably. My dog loves napkins, and they just come out in his waste. He once pooped out ONLY napkin so.......
