Same story here except DS was 15 and it ended up in a dramatic and traumatic rush to A&E at 11pm one night when he couldn't wee AT ALL and was crying to me with fear. It was so so awful for him, they gave him gas and air while they tried to snip the end of his foreskin so that they could insert a catheter as they couldn't even get the narrowest catheter back up. I'll never forget it, it was like watching your child being tortured. And still they couldn't make a gap to let any wee out.
They ended up having to call the emergency surgeon out in the middle of the night to do a procedure under general anaesthetic so that his bladder could be emptied. He stayed at home with a catheter for a week then was admitted for a scheduled circumcision.
They said that in my son's case it was caused by a condition called BXO which can get worse as goes on and even circumcision may not prevent a bit of a re-narrowing of the urethra.
If they're advising him to have a circumicion young, OP, I would seriously think about getting it done. I wish we had never had to put DS through the trauma of that nighttime rush to A&E as a teenager. He will always remember it.
Despite the circumcision he had further re-narrowing a couple of years later just before A-levels and had to go in again for a procedure to have his urethra expanded (thankfully he anticipated this in time for it not to be quite such a traumatic experience but it was still a day case).
Ultimately he now has his own catheter type things that he has to regularly insert into the end of his penis to keep the urethral tube open as it can close over over time if you don't. He is on a programme to self-refer if he has any further issues through his adult life.
I feel sorry for him because what 19 year lad wants to be worrying about that? I also feel guilty because perhaps I should have done more when he was young? But not having a penis myself how am I supposed to know what's normal? All the baby books tell you to let the foreskin separate on its own and not to pull it when cleaning. I too noticed the ballooning, but the same thing had happened with his older brother for a while and then it just resolved. Over the years no medical person ever said they needed to examine him, they just issued a few prescriptions for antibiotics for UTIs. It was only when I really pushed for a GP appointment because yet again it was disrupting his life that the GP said on the phone that she would need to examine him at that one. Unfortunately 2 days before that GP appointment his urine flow stopped completely and that was the traumatic A&E visit.
Please, mums of boys, if you have any suspicions at all that something isn't right with your son's penis, don't assume that all will be ok. Go and see a GP, even if it's just for reassurance.