Recovery from sludge in the urine

Question
Dear Dana,
We live in San Diego CA, My 4 years old new Zealand was diagnosed with sludge in the urine last monday, Dr Cecil (an  exotic vet)did a Catheterization and flushing of the bladder. The recovery was painful, we finished the treatment last night. He seems happy and he is eating ,walking and even running a little. I am concerned because all I can find in his litterbox are a few very small drops. He is peeing normally, I spoke with the Dr yesterday and he suggested to wait one more day, but nothing has changed today. He doesn't want to eat pellets (timothy# is eating a little hay #timothy) and some dandelions,carrots and romaine. And some banana. The medicine he was taking is SMZ-TMP, Reglan, Buprenex and undersking fluids.  What can I give him to help him go to the bathroom? I read about pineapple juice.Also, which kind of veggies do you recommended? The Dr told me that the blood test was all good any of his organs are damage.
Thanks a lot

Answer
Dear Mharsela,

The first thing to make sure about is that your bunny is actually making urine.  I'm confused about this situation, because in one sentence you say that all you find in his litterbox are a few very small drops, but in the next sentence you say he is peeing normally.  These two things seem to contradict each other.

Please ask the vet to palpate his bladder to make sure he doesn't have a full bladder that he's unable to completely evacuate.  Sometimes a catheterization can cause problems with the bladder wall muscles (even in humans), and treatment is necessary to restore normal bladder function.  There are medications that can increase the tonus and strength of the muscles of the bladder wall, as well as those that can relax the sphincter of the bladder.  (Your vet will know these, but just in case s/he is not familiar with them, please write again if you need the names of the drugs.)

Pineapple juice won't help with this.  But if he is also not producing poop or eating, then please see:

www.bio.miami.edu/hare/ileus.html

I hope this helps.

Dana