Hi again!
Yeah, sorry if me last post was slightly confusing.
Elora is right, their poop should be a dark colour. When Ja Ja had probs, it was his urate that turned pink, but had red pieces of food undigested within the main poop!
When I first saw your pic, I just noticed the pink colour, and the pink looks like urate with no main poop. Hense, food can do that.
It's more the lack of main poop I would be worried about. If his main poop is that colour, then yes, I wouldn't think food could do that.
All I can say is that if he were my baby, i'd get him to the vet with a sample if poss so they can test it. They should be able to tell you what's going on and what can be done.
Good luck, and I hope he picks up!