My cat is a 5 year old male. He's never had any health problems until now. His attitude is completely normal and he seems lively but he's sick. We don't see him eat anything except one or two tiny bites, but he vomits it up soon after. We have tried literally every flavor and brand of cat food that we can find. We've tried milk and various human foods too. He acts like he wants to eat - meowing, begging for food, etc. - but he only sniffs food when we give it to him and then licks it a little and walks away. We've tried heating the food up, different material plates, locking him alone in the bathroom so he's not around the other cats, everything we can think of. He must eat something when we're not looking though, because there is always a big pile of vomit in the morning. The vomit doesn't seem to have bile or anything in it. We don't think he's getting into any poisonous substance or plant. We also haven't seen him poop in weeks. We've taken him to the vet 3 times but they don't seem to know what they're doing. They make one guess after another but nothing addresses the vomiting and nothing makes him better at all. His blood work looks clean and the x-rays don't show any blockage. Every time, the vet gives him an enema because he is constipated and full of feces. They have given us different laxatives to try but those haven't helped. The vet thought his colon wasn't working right so she gave us medicine for that, but it doesn't help either. And like I said, they aren't addressing the vomiting issue. Even though he acts normal, he is starting to lose weight. I know he can't live much longer like this. Please help me.