Pain in right abdomen and flank back. hurts worse at night. have had tons of tests/scans/images (in profile). what could it be?

Pain: That area of your body also contains your right lower chest,, kidney and I would include your back. Given your negative work up I would say this does not appear to involve your stomach, colon, gallbladder or kidney. Given it is worse when you lie down I would be suspicious of chest wall pain or pain involving ribs or vertebrae.

You tweaked your back: . If all of your tests are normal. If there is nothing broke. If there is nothing abnormal in your laboratory. If all your lab and x-ray are normal I suggest you see either a chiropractor or a good doctor of osteopathic medicine. Sometime you can just get manipulated, straightened out, and everything goes away.