Core Spasms Agony...T5

The causes are almost always illness. Where is the $64,000 question. Get your urine checked and think carefully about your diet and bowel program. Even if nothing has changed your body may have changed it's response to something you have eaten without problem for many years. Get your urine checked first. If you normally try to handle infection by greater care of your diet and/or other ways of supporting your immune system, do those things.

Bloating causes me no end of spastic responses and it has taken me years to nail down causes and adjust my eating. Infection cranks up the general level of muscle tone and spasticity to cause much more pain than those blessed periods when I am infection free.

I think you may be right, as I've also been having back/kidney pain and noticed blood in my urine. I don't have a fever or anything, which I normally associate with a bad UTI...