Aww poor Toffee 
My DDs piggie (about the same age as your piggie) deposited several patches of blood on the puppy pads overnight , we took her to the vets that night, got the antibiotics.
She improved , took her meds , she wasn't in any pain when she peed .
We cut right back on any dark green veg, did some adjustments to her pellets (you need to do slowly) increased the % of selective (lowest in calcium that I could find, they were on Burgess Excell)
We knew it was her, the cagemate had a white rump/bum.
We did a couple of quick bum dips rather than wipe , her fur round her bottom got a bit claggy, she did feel better after,
I'd like to say it ended well, but sadly, not.
She was on her meds when she went to Boarding and they kept a close watch on her bedding, she was improving.
When she got home, we noticed she was peeing blood again, but it tailed off ....then we had to start Critical Care so we knew she was on her way out.
As she wasn't in pain, we kept a close check (her and GP6 were inside) she died a few days later.
I had some powder (Probiotics + Vit C) to go on the veg but she was struggling to eat by the end.
I did the "Shall we take her back to the vet/shall I not" but I'd had one of my other hogs PTS the month before and I knew I didn't want piggie to go through tests,scans etc.
I knew she'd go and provided she was comfy I'd just let her.
Would I do anything different? Probably not.
We took her to the vet the day we saw blood
We trusted the Boarding to do what was necessary (including PTs if needed)
She lay in her cage the last day , with gP6 (DH was home)
DD came home from school, piggie died about an hour later.
I think if Toffee is showing signs -crying,grinding then she might need painkillers (they love them)
You might need to syringe feed and syringe fluid .
Keep a close eye and keep her comfy. Go by what she needs.
We didn't have the outcome we wanted but our guinea had the calm end we wanted .