Uncircumcised. Forskin on 2 year old stuck?

So my two year old roams around naked because we are potty training. from time to time he will stretch his penis out sliding off the edge of a dinner table chair. And this is the 3rd time in his life, (he's 2. ) that his penis was red at the top and oozing green or yellow discharge from the skin getting stretched behind the head. I think that's what it is. I read about it the first time it happened, put breast milk on it and I was gone the next morning. but this is something that keeps happening, but not too often I'd be scared. any other moms take there toddler to the doctor because of it? I don't wabt him getting chopped up down there if this is something that happens normally.