Parasites, but that might or might not have been the problem. Panacur is kind if a "cure-all" a lot of reptile vets prescribe - it's so gentle it can be used on frogs so it's not really a worry. I had a really good reptile vet tell me that finding parasites in snake poo means nothing, as it's almost impossible to tell the one that are harmful to snakes apart from the ones that just live in mice that the snake passes. So who knows. I don't think I'm all that qualified to recommend anything, but getting your hands on some Nutribac wouldn't hurt.