Yeah, they’ve made it harder than it used to be. I expect they may one day go to a Fellowship required, but there’s been a shortage of Fellowships overall, from what I understand.
I used to qualify for sitting for that board, but then they tightened the type of practice experience one needed.
Most likely, he did a 3- or 4-year urology residency, and a 1- or 2-year pediatric urology fellowship afterwards, especially if he wanted to be a sub-specialist (for instance, female pediatric urology).
Students do clinicals starting at the M3 year if not before, and that’s where they often find out what they do (or, more commonly, don’t) want to specialize in.
Anecdote: Years ago, I read about a pathologist who in the meantime had become an expert in determining whether an unexplained infant death was SIDS, abuse, or some other condition. When she was in med school ca. 1970, she loved studying cancer and the night before her oncology rotation started, she had trouble sleeping just like a little kid on Christmas Eve. So, she walks in and introductions happen, and the oncologist says there’s a woman on the floor in her 40s who had a type of leukemia that, at least at the time, had no useful treatment, and no matter what they did, she would not live more than a few months, and by the way, you have to tell her this. So, Excited Medical Student walks into the room where the terminally ill woman is sitting up in bed with her husband and kids nearby, and the faucets turned on. THEY ended up comforting her, and that day, she knew that she could not be an oncologist.
I wish the practice experience requirement were looser. My current employer pays slightly more for each board certification one has, regardless of how much one is even using it. If I could fulfil the practice experience requirement, I could just study for and pass a test, and I’d get a raise.