I had spinal fusion 7 years ago and now i suffer from chronic lower back pain - is this normal?

Yes: Unfortunately, its not uncommon to see low back pain recur after back surgery. I recommend you follow up with your surgeon.

Not Typically: If you are having severe chronic low back pain it is worth investigating to try and determine the cause. There may be some correctable problem. Alternatively, you may be a candidate for an implanted spinal cord stimulator. This might provide excellent pain relief.

Sometimes: When having a spinal fusion, you are typicalky taking a bad situation and making it better, not necessarily restoring the back to normal. Ongoing changes that may be affected by someone wirh a prior fusion can lead to back pain later on in a small percentage of fusion patients.