What Causes Diarrhea And Nausea After Kidney Surgery?

Hello, I had right kidney surgery about 6 years ago. I have had soreness since and i feel I might have some scar tissue lingering. Recently (today especially) after eating Mexican food (6 hours ago and it took about 20 min after I ate) I had diahrrea and nausea and my right side is slightly swollen all the way down my leg.