Usually is. How much of a problem it is depends on the findings.By age 5 circumcised males may develop a narrowing of the urine outlet of the penis.It is less common for uncircumcised. If they have a mild inflammation at that site, conservative treatment with meds may improve it.Often it provides enough of a problem that the kid needs to have the outlet widened(dilated) by a urologist (under anesthesia.
Possibly, yes. Yes, this could be a serious problem. Take him to the pediatrician.