4:30 is early! A midnight potty break before bed is good. When he wakes up early, I would try taking him for a potty break to see if he needs to poop. If that is the case, his pooping schedule may be off. You can adjust that with more exercise during the day/early evening, which hopefully will make him take care of business before bedtime. When Teddy hasn't had enough exercise, he often he needs to go potty early in the morning.
Your boy might be an early riser because of his last home. I am not a morning person, but my boys start looking for breakfast around 5:30 am. I stumble out of bed, feed and potty them, and then go back for another hour or two of sleep.
