My wife has herniated disc on lower back at L5. Wanted to know if surgery will fix this issue without any side-affects.?

Imperfect solution. Surgery is never without side effects and while it can fix problems it is a damaging process. Surgical wounds leave permanent scars. Low back surgery is tricky, some have vast improvement and others none or even new problems. The neurosurgeon will look at each case in detail weighing the risks and benefits based on the unique problem. No two are the same. Surgery should usually be last resort.