My rabbit was spayed the day before yesterday, she was given to me awake but did not move, the next day she ate some vegetables, a small piece of apple and lettuce in small quantities, in the morning she made two poops with mucus, a few hours later she made a lot of white and orange mucus. The vet is giving him simethicone, metoclopramide, meloxicam and sulfa antibiotic. He did not want to eat, should I give him a syringe?
Mucoid enteritis isn't a specific disease, it's more a description of what happens when a rabbit's gut microbiota is imbalanced, giving the rabbit a belly ache and causing the intestines to produce mucous in response to the irritation. Given the amount of drugs this poor bunny has been given in the last few days, I imagine she has the mother of all gut aches!
If at all possible, you should try to get some herbivore probiotics, e.g. Benebac paste/powder.
If you can't find that, even trying to get some plain yogurt into her might be helpful (use a syringe to get a tiny bit in if she doesn't want it). Give her fresh hay and keep it scrupulously clean; same with water. If can find Critical Care for Herbivores, that is a good nutritional aid that you can mix with water and give via syringe if necessary. After a day or two of syringing, many rabbits feel better enough to eat it on their own.
Even though sugar is generally not good for rabbits, when a bunny is off its feed, I offer anything and everything that might be nibble on - apple, comfrey, chickweed, dandelion, grass, anything going in to keep things in the gut moving. Like
@Preitler says, sometimes annoying them can make them take a bite.
Another thing we've found can really make a difference is plain old TLC. We've had bunnies that would only eat and drink when they were being held and petted (and they weren't necessarily people-oriented to begin with). Even though it might seem a good idea to leave them quiet and alone, some gentle encouragement has been helpful for ours.
Hope your bunny rallies!