sorry nobody replied sooner, my city is right now under state of emergency due to worst flood the city has ever seen, so I'm not around too often here.

anyhow, Caspian is right, a frog is still recovering after it's stress + adapting to his new home. would you please answer to all "trouble in the enclosure" questions, so we'd get the whole picture.
not eating for 4 days after such experience he had is pretty normal I'd say, but you're right in worrying about it. right now the question is if he was injured in anyway. does he have any visible injuries? does he behave any different from what he used to before the fall, any changes in his color at all? did he poop after the fall?
it not directly has anything to do with the fact he is not eating but yes coco bark is no good, you need coco fiber. coco bark has a high impaction risk if swallowed as well as based on my experience bark doesn't hold humidity as well as fine coco fiber does.
can't say much more, please post your answers to "trouble" questions, and we can go from there.
i must say I'm very happy you find the frog and it ended the way it did.