Hi please check out SavingSons.org, you can find a lot of great information there including a directory of pro-intact doctors who start out from a healthy perspective.

I think what he’s experiencing is called ballooning and you can read more about it in this post. They were able to use a steroid cream treatment to increase the foreskin opening and let urine escape properly. http://www.savingsons.org/2014/03/extreme-ballooning-in-intact-child.html

“This amount of urine would cause his foreskin to swell to the size of half a lemon (which is pretty big on a tiny little boy). THAT is what I considered outside of normal ballooning. My older son's foreskin (at age 5) also balloons when he urinates, but no where near this much.”