I have a small sinus in my left hydrocele. a few amount of white liquid comes from the sinus. i was operated .the sinus is dry. but liquid comes?

Interesting: "sinus" discharging small amount of white liquid is likely only skin deep & possibly from a hair follicle or tiny sebaceous cyst at surgical incision site. Think of it as some skin cells, buried under the skin, producing liquid that has to escape. Can be dealt with by a mini surgical procedure to excise the "sinus". Your urologist will be able to take care of this. It isn't serious.