Hypospadias operation can lead to narrowing of urethra as some stricture can happen, if urine stream is thin and urine is getting obstructed due to either stricture or phimosis, back pressure changes can happen and damage the kidney. There is nothing like too much widening and can't control urine. If by chance the nerve gets damage while operating then rarely it can cause incontinence but usually doesn't happen as surgeon's are well aware of anatomy of nerve, by chance patient has abnormal nerve route which is also rare, then this complication may occur but it goes further rare.