Having pain through spinal cord during orgasm. Had 3 previous lumbar surgeries. Is this likely a spinal problem? Having another epidural next week. They want to send me back to uro/gyne. It hasn't helped previously.

More likely than not. Given your history of multiple spinal surgeries, it is very likely that your pain stems from an issue with a spinal nerve or branch thereof. The genital area if innervated by lower lumbar/sacral nerves. With a symptom like yours, previously pleasurable sensations are being mixed; cross over effect. Assuming no vaginal lesions, YOu need to consult your pain medicine MD or the surgeon.
Well. Many possibilities here. First it may be a positional issue Try changing positions. Now 3 back surgeries is significant. You have a lot of scar tissue. This may be an issue. Obviously you have issues anyway if you are still receiving objections so sounds like the surgeries failed. So may be a chronic issue. See your doctor and get your exam but your issue does not sound acute .