I recently had an operation to repair my prolapse bladder but still get pain in my pubic bone on right side and under my buttock any idea what it is?

Unsure. Some unusual, pain can occur for many weeks after surgery. If this pain is significant, myth should see your surgeon and be sure there is nothing serious going on.
Post-op pain. Pain may be related to surgery, possibly a nerve irritation. Pain may improve with time. Talk to your surgeon. Try ibuprofen.