Hes now seen the specialist vet, his gut swab came back saying he had an inection, the vet thought maybe he'd had liver or heart failure due to the infection which can cause bleeding, there was talk of an operation if the infection had spread to his organs to see the extent of the damage and maybe not waking him up afterwards.
Thankfully an ultra sound confirmed all organs are in working order with no damage so no operation. We are still none the wiser as to where blood has come from and a further xray showed no extra fluid has accumilated since his last xray which is good. He has now been put on an intense course of antibiotics for 1 month. By looking at him and watching him you would never know there was anything wrong, it was only the clicking which was unusual, this has now seeemed to stop. Hopefully he will come out of this all good.