Wow, that is awful. They are WRONG that there has to be blood for it to be Crohn's. It sounds like there's a chance he could have a stricture, so I think you need to get an MRI as well. Next time take him to a different hospital. This could definitely be Crohn's.
"For this thing I besought the Lord thrice that it depart from me. He said, My grace is sufficient for thee: for my strength is made perfect in weakness. Most gladly therefore will I rather glory in my infirmities; I take pleasure in infirmities, reproaches, necessities, persecutions, distresses, for when I am weak, then am I strong" 2 Cor