I had l5-s1 spine fusion and a L4 foraminotomy in several months ago, is there a way to relieve back pain radiating down my left leg?

Several ways. Some of this depends on what part of the leg is affected and the underlying cause. Treatments include medicine, injection therapy, pt, spinal cord stimulation and further surgery.
Post-surgical? Is this the same pain as pre-op? Or is it a new pain? Sounds like either the operation wasn't totally successful or a new problem has cropped up. Either way, see your surgeon for an opinion. Could be a new pinched nerve, a hardware issue with the fusion, or a nerve injury of some type. Is it getting better? Worse? Compare the pain to pre-op. Better or worse? All questions to discuss w/ ur surgeon.
Yes. Unless you are suffering from permanent nerve injury related to the problem you had recently treated, most pain radiating into the leg is treated well with medication, injections, or surgery (assuming a spine etiology). Once the exact location of the nerve compression is identified any number of interventions can help you. See a spine specialist to walk you through the work-up.

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