If a bunny is straining to pee but only produces a few drops, a urinary tract infection is the first thing to suspect. It can be painful, and pain can make a bun stop eating/ eat less, and hence produce a lot fewer droppings.

Right now the most important thing is to get his tummy functioning. Is he eating? Will he take a treat from you? What medicine have you been giving him?

Tummy discomfort/gas can be treated with 0.5-1 ml baby gas drops (simethicone). It’s not absorbed by the body, it only acts locally in the GI tract and it’s ok to give on suspicion of gas according to Medirabbit. It’s much used by bun owners, I always keep a bottle at home.

You can also do a very, very light tummy massage, but if he has a UTI, his lower tum could be sore so he might not want you to touch it. Here is a HowCast video on how to massage a bunny: http://www.youtube.com/watch?v=JnuxGLa2reg

Fluid intake is important. You can syringe feed water but it must be done with great caution. If he’s eating greens, you can serve them dripping wet. Some members have had success with adding a bit of cranberry juice to the bun’s water – but always serve plain water as well, some buns won’t touch water that tastes funny.

A urinary tract infection needs veterinary treatment with the appropriate antibiotics. If he isn’t eating, he could deteriorate very quickly. I’d call a vet after 6 hours of refusing all types of food and treats. Buns can’t go with an empty tummy or their GI system starts to shut down (GI stasis).