Lower back pain three months out. very limited to what i can take. no nsaids due to gastric bypass. any suggestions?

If you do not have significant hypertension or chronic kidney disease, a short course of celecoxib (a cox-2 inhibitor which is not contraindicated in most stomach conditions) with other med for chronic pain such as gabapentin, pregabalin or duloxetine along with physical therapy. Alternative therapy is steroid injection or ultrasound ablation. Of course, cause of back pain needs to be identified.