I have read your post and I pray you have a healthy Hen in the end. I have a Roo that I spent $1253.00 on this past month who could not poop. He was in the Bird Hospital for 4 days, tube fed and on an IV. He had an obstruction in the area right below the crop. He also had a yeast infection, and worms. This was diagnosed by x-ray. She gave him a digestive enzyme that aided in the passing of small stones he had eaten as well as some of the worms had died and were unable to be passed. I know this is different from your Hen. Just have faith, remain positive and pray for a quick recovery.
When he came home we had to tube feed him, give him 2 different injections , and loads of other oral meds. The hardest thing to do was the tude feeds, if down the wrong pipe we could have killed him by getting fluids in the lungs. We were told by friends and family we should of put him down, but the vet was confident in his treatment.
I am pleased to say he is very very healthy now and completely recovered.