So sorry to hear your cat is unwell. You must be so worried.

 

Maybe constipation?

 

Is he a house cat? Does he go to toilet regularly?

 

I got a couple of links which might help.

 

http://pictures-of-cats.org/home-treatment-for-cat-constipation.html

 

http://pets.webmd.com/cats/cat-constipation-and-fecal-impaction

 

 

Maybe you can ring up your vet for advice even though you can't take him.