What does his poop look like?
What is his home like?
As for his feed, do you have the nutrition label from it?
Pictures of his poop, setup, and him would be very helpful.
I have been fortunate enough to not have a lot of experience with disease. Coccidiosis comes from eating their poop and usually only occurs if they are living in dirty conditions.
The pictures and answers to all of the above questions will help with diagnosis, but take it with a grain of salt...