Wife has severe pain in lower back/butt pain started around 38 weeks pregnant, still there post partum. x-ray norm, what is it what do we do about it?

Sciatica: This is a fairly common problem. The position of the baby can put pressure on the sciatic nerve and cause irritation - even some degree of damage in very sensitive people. A physical therapist, accupuncture or specialist massage therapist can often help a lot. It's good that the x-ray is normal, but nerves don't show on x-rays. This should improve w/ proper help. Congratulations on the baby!

Sacroiliac joint : she has inflamed sacroiliac joint. May need to take anti inflammatory , physical therapy and or steroid shot in the sacroiliac joint.