Yay for POO! I told ya
Xrays:
Im no vet but "going off common sense" i would think a blockage would show a vacancy (or a somewhat extremely small following) in the intestines behind/after the "blockage". In the pictures it seems that he has food being processed all the way to the vent.
Edit: Also that poo suggest you bump up your mistings. Melleri take a long time to start drinking and once they start drinking they drink for a very long time. Thirty minute mistings are not uncommon for these guys/gales. One other thing i would be sure your not using products with D3 (gut load or supplements).