What Causes Soreness And Tenderness At The Site Of Incision?

I am 46 yrs old. I am 5'7" and weigh 140 lbs. I have had 3 c-sections and hystorectomy. I have been cut in the same place each time. The bikini cut. I can't rid of my stomach. It is sore and tender and it hurts. It feels like something is sqeezing my stomach on the inside. What could it be?