What do you do for water?
Kale is actually not recommended as a daily staple, as it binds with calcium and makes it harder to absorb. How many supers does he get on those days. 5-6 is generally the most you want to give at a time, because even though they have less chitin than mealies, they can still cause blockages.
Can you feel a blockage in his belly, like a hard lump just before his hip bones? You can try 20 minute soaks in warm water (you'll have to change it out once or twice to keep it warm). I actually don't know a specific time frame of how long is too long for a beardie, but if you have a qualified herp vet in your area, I'd give them a call. And remember that just because a vet says they see reptiles, doesn't mean they know what they're doing. Ask how many reptiles they see in a typical week or month, and try to find someone who sees at least several a month. I once worked for an "exotics" vet, but in the 4 months I worked there, I think there was one rabbit and zero reptiles seen.