I'm 4 weeks post op from a fleur de lis tummy tuck. I have some yellow puss coming from the T section of my scar.

Soreness and redness and drainage can all be associated with infection. Make sure you see your operating surgeon so he or she can properly examine and evaluate and treat you if necessary. Good luck!

Most often the drainage is not pus.  It is still something that needs to be followed very closely by the surgeon. Clear yellow drainage is better than thick opaque drainage.