I've had major abdominal surgery and have never heard of staples being used inside the body. They used stitches inside and staples on the outside when I had surgery.
Many years ago I had minor abdominal surgery and did get an infected stitch and it drained...just like you mentioned. It did close up and heal.
If they used mesh for your surgery, I'd certainly check into that. Many people have problems with the mesh and it causes pain and other things. There could be some nerve involvement that is causing the hand and arm jumping. And maybe it is the medication, too. I could be wrong. I am not a doctor. But, if I were having these problems, I'd start asking questions.
I hope it's something simple and you are feeling better in a hurry!
Sherrine