Severe constipation in cats.

[GwennieF]

My cat is suffering with massive constipation at the moment. He's currently in the veterinary hospital and after a series of tests and radiographs, I've been told that he's really badly constipated. I know that doesn't sound that serious but he's 17 and I've been really worried about him - even had the "Harry might not be coming home" conversation with the DCs before we knew what was wrong with him.
Anyway, my vet has said that the chances are he'll have to be on small doses of lactulose long-term - has anyone any experience of this? How do you administer it? I thought it was prescription only? Is it expensive (I know it shouldn't be a consideration but money is tight)?
Other than that, he's in grand shape for an old boy - blood tests all came back clear... Just looking for other people's experiences really.

[coppertop]

My cat had lactulose for a short while. It was squirted into his mouth with a syringe (similar to the way you would give Calpol to a baby).

I can't remember the price but it was fairly cheap. It actually cost less than the stuff I buy for my children!