guinea pig excessive urination

Question
Hello
I've had my guinea pig, Toby for 4 years this month and recently it appears as though he is urinating excessively, his whole cage is soaked after 3 days and the smell is really quite strong. He lives in the house in a big cage so the smell of amonia is very strong at this point.
Is there a possibility that he is unwell or is he just drinking too much water? I'm very worried about him because his rear end and tummy is covered in urine so he's obviously just sitting in it. He never usually needs his cage cleaning out as often as he does at the moment, usually a week but right now after 3 days the cage is unfit for him to sleep in and has to be cleaned out more frequently.
Any suggestions?

Thanks

Answer
most likly he has either an infection or a rectal dysfuntion, it is not a good sign and he needs to see a vet really, in the mean time make sure he is kept clean, the last thing ou want to is keep him sitting in his own filth as that will lead to all manner of problems.

best of luck