I had a fistuletomy 50 days back. I used to get slough discharge in a very small quantity, which was easily washable. Since yesterday, i have noticed a white layer on the surface of the wound. I tried to wash it off, but it isn't going. I tried soaking it in sitz bath and then washed it, it still isn't going. I have attached the image for your reference. Please advise if this is normal or if should i be concerned? I had a review from the surgeon 1 week back, and he said my wound was clean and healing well. I did not have this problem at that time.