I had a house rabbit for 8 years. When he was 7, I noticed he stopped eating and pooping, and would just lie down in a corner, and not raise his head. It was very frightening for us to see and we didn't know what was wrong with him. His teeth were fine. The vet suggested that we get papaya enzymes and crumble one up in a wee bit of water and feed this to him with a dropped. Incredibly, it worked! He didn't want to swallow anything but we kept at it and got that papaya enzyme into him. Apparently, he had been eating drywall in the basement and we didn't know it! It had formed a clump of cement like blockage in his intestine. The enzyme blasted it away, and within 24 hours he was pooping again, and started eating the next day. From then on, we gave him a papaya enzyme every day, sprinkled on his banana pieces. He loved it and didn't get sick again.