How can I treat spasms after tummy tuck?

The procedure used to tighten the muscle grabs some of the abdominal muscles with the stitches. This can cause pain and spasms of the muscles. It should get better with time. Make sure not to strain after the first 6 weeks after surgery.Best of luck, Dr. JSB

Since the rectus fascia is plicated during an abdominoplasty, it is not uncommon to have pain in the mid upper and lower abdominal pain afterwards.  However this pain is limited and gradually resolves.  Since it seems to be worsening, I would discuss with your surgeon immediately.  It may be that a muscle relaxant like Valium may help.  

Muscle spasms are not uncommon following a tummy tuck, particularly if the plication or repair was large. As your ability to stand up straight improves, this may tug on the repair and initiate a spasm. A low dose muscle relaxant (Valium) may help at this stage. These typically resolve over a period of several weeks. 

Best to see your surgeon ASAP! I might inject long lasting local to area. Or try moist heat to area.