My son had hypospadias repair at age 1 and meatoplasty at 3.5, which he now needs again. is this common? are there possible complications for repeats?

Yes, can recur: Meatal stenosis is quite a common complication after hypospadias repair. Usually taken care by a meatoplasty. Repeat meatal stenosis has occurred which is why meatoplasty needs to be repeated. Ask your urologist whether or not a different technique will be used or whether a larger opening will be created than last time. Consider a second opinion because meatal stenosis can recur time & again.

See below: Meatal stenosis is one of the more common complications of hypospadias repair. A secondary repair is usually curative. Requiring additional surgery implies potential other issues and merits further investigation. Consider getting another opinion prior to additional surgery.

Yes and Yes: Each case is different but if he is having trouble voiding after having had a meatoplasty, I would normally recommend a 2 stage procedure. This is just a short answer since I don't have all the details. I would consider a consultation online for this issue.