I am willing to learn to tube feed, I am also willing to go get a rectal thermometer.
The doctor's page you posted with those products is the same doctor offering the formula I posted earlier as a treatment for Vent Gleet. I am now more convinced the bird's issue is vent gleet and the prolapse is a symptom. We have been keeping the area clean but the bird is becoming more lethargic and has not eaten. I have some plain yogurt, dark Karo syrup, mineral oil, cracked corn, and starter/grower mash all mixed together for a food offering. I have water with electrolytes and probiotic available, and some chick grit. The crop remains soft and filled with fluid but not balooning just obviously containing fluid. Still no poop but the feathers below the vent are constantly wet so some fluid is passing.