Blood in urine and green stool

Hi, I posted the other week about my cat urinating and pooping outside his litter box. He had previously been checked by vets all was fine but this was in 2015 so a long time ago and not long after I posted about this issue problems quickly developed. I'm now not bothered at all about him going outside his litter box as it means I can keep on eye on what is going on with his urine. I noticed he was weeing nothing but blood 4 days across. It was thick red blood, didn't even look like urine and it was maybe two tablespoons of blood like a nose bleed. He also cries a lot since this started happening. I took him straight to vets who said cystitis most likely and probably not bacterial but they would give him a 5 day course of antibiotics just in case and that within 24 hours the blood should stop even within 30 mins I might notice blood stopping as he got a strong antibiotic injection and painkiller. Well it hasn't been the case. He only has two days left of antibiotics now and should in the vets eyes be cured if its cystitis but the problem is getting worse. He's very clingy but no decrease in appetite as of yet but a lot of crying and wanting to just be cuddled. He's now weeing very dark brown blood and it's literally cup fulls of it. He won't go inside litter tray at all now which I'm glad for as it means I'm able to keep an eye on what's happening. His urine also has dark floaters in it too like pieces of paper but blood. It's really a lot of dark brown blood. And this morning he's passed a green stool. I have rung vet and waiting for call back but next step is a urine sample... Anyone have any ideas what could be wrong with him? He's only a year and a half old. Thanks

Oh that sounds awful. Years ago we saw our cat Pushy peeing blood and crying. We took him straight to the vet and he went on antibiotics which cleared him up very quickly.
It sounds like there is something more serious than cystitis going on in your cat unfortunately. I hope the vet can give you some answers, and they need to run more tests. Poor kitty, and he's so young too.

I'm hoping its nothing too serious and treatable as this cat is literally my whole world. He's my best friend. My shadow. My everything so i couldn't even contemplate anything serious being wrong with him. I had a panic attack when i first saw the blood. I just want him  better. i've handed in a urine sample so hopefully get to the bottom of this soon. he seems well in himself so I dunno what's causing it. Thanks for your message 

The vets have annoyed me this time. Usually very good and I had to push for them to send his urine off and do bloods. They said they aren't worried cause they can't feel a collapsed bladder, sorry but his symptoms don't just indicate a collapsed bladder. They seen themselves he's passing so much blood. He's crying. He's not himself and he's just passed a green soft stool again. I know my own pet and he's not himself and they are really frustrating me to be honest. I am pretty sure there's more reasons for blood in urine that isn't just cystitis or a collapsed bladder!