I had SculpSure on my stomach area. I experienced diarrhea the next day

Diarrhea should not be a complication or sequelae following a sculpsure treatment. This laser focuses on the subcutaneous tissue and destroys fat cell membranes. The destroyed fat cells are the picked up by the lymphatics and excreted. Most likely, the diarrhea is coincidental to your treatment and possibly the flu. Please consult with your doctor if this persists.

Sculpsure is a laser treatment that destroys fat cells only a few millimeters below the skins surface, it would be extremely unlikely to trigger the GI concerns you experienced. The fat reduction takes place over many weeks. This seems to be an unfortunate coincidence.