Veterinary questions? Ask a Vet for Answers ASAP
I am sorry your rabbit isn't eating or passing faeces. This can be very serious and if it continues then it can become life threatening. If things don't improve quickly, you will need to go to a vet for urgent medical intervention.
It is vital food and water are consumed and it is a shame the Oxbow isn't going in easily.
There are other options to try such as pineapple juice, freah coriander, banana, parsley or jarred vegetable baby food. These should be fed frequently to encourage the guts to start working again.
However, this can be life threatening so it is important to get your bunny examined promptly if things do not resolve in the next few hours.