Can You Get Back Pain Relief with a Tummy Tuck?

Thank you for the question.
   Part of the tummy tuck operation involves plication (re approximation) of the abdominal wall muscles that have spread with pregnancy. This reconstruction likely strengthens the core and MAY help with issues such as lower back discomfort (assuming there are no other  anatomic causes of the lower back pain).  I would caution you however not to assume that your lower back pain will be resolved after tummy tuck surgery.
Best wishes.

The purpose of the abdominoplasty is to remove excess skin and tighten the abdominal muscles.  I don’t think this will impact the back pain directly. Relief of back pain is usually accomplished  in the form of walking and strengthening core muscles.

An preliminary report published in 1990 suggested that Wide Abdominal Rectus Plication (aka the WARP abdominoplasty technique) produced some back pain relief in 24/25 patients treated.
However, this has not been substantiated and should not be the primary reason you seek abdominoplasty .
If i can explain. Your spine depends on a delicate balance between your stomach muscles and back muscles. When your stomach muscles are weak you may have an abnormal posture which creates excessive back discomfort.
Think about how it feels on your back when you have been sitting "Indian-style" for a while.
This is the reason orthopedic surgeons and spine surgeons will often prescribe a course of physical therapy to strengthen your abodminal muscles. It is also why Pilates and Yoga core strengthening exercises can improve minor back pain. I perform Pilates after a long week of surgery and I find dramatic relief from back strain.
The muscle rearrangement that occurs with abdominoplasty can enable you to use these stomach muscles in a more normal fashion and improve back pain but it should not be the sole reason you seek surgery.
In fact, in the early postoperative period, you may experience a greater degree of back pain you feel due to excessive bending forward from your tendency ot releive the pull felt by tightening the skin.
I hope this helps!