Lower back pain, cramps and numb digits

Patient: I am 59 yrs old and in reasonably good health. I have high blood pressure mostly untreated but that isn’t the issue or at least I don’t think so. I’m having severe lower (just above the butt) back pain, coupled with stomach cramps that feels like rats eating my intestines and just recently, my fingers are going numb and no amount of flexing has alleviated the symptoms.

Doctor: