My wife was just diagnosed with spina bifida occulata (age 23). they said it's mild. her tailbone hurts. what's the treatment for something like this?

Usually no treatment: I do not think the tail bone pain is related to to spinal bifida, which usually is asymptomatic.

Usually nerve block: Condition occurs in 10% of population and is not serious, should be treated conservatively, usually nerve block injections.

PT: The spina bifida occulta, may or may not be related to her symptoms. It most likely is an incidental finding and unrelated. Tailbone pain (coccygodynia) is treated with pt, exercise and nsaids (ibuprofen etc). It is usually self limited.