Just about to go out, visited the loo and urine like strawberry squash (more than rose!) I was really alarmed. I checked my INR - fine at 2.9.
I am so very thankful for this site. I found lots of references to blood in urine, so having established that warfarin in itself was unlikely to cause this I took myself off to the local clinic (in Spain) to get checked out. The first thing was a urine sample and then I showed the doctor the result of my INR test that morning. Two days of powerful antibiotics and everything is back to normal. I didn't find out what was wrong but assume it was a urinary infection. No symptoms at all apart from going to the loo more frequently.
Worth knowing the possible side effects (for warfarin users).