Stent Removal/White Substance on Penis

Hello,

I had Kidney Stones removed on 04/18/12.  A Stenet was placed after the surgery and it was removed on 04/23/12.  I am uncircumsized and when I pull back my skin, it has a white substance all around my penis and it appears to be some dry skin particle.  Plus, my foreskin seems to be swollen.  I feel no pain when I urinate but when I clean my penis in the shower, the very next day the white substance is there.  Is this because of my surgery and should I be worried?