Welcome to HealthcareMagic forum.
It appears your son is suffering with an infection of upper respiratory system. Though it is virus (flu
) that commonly causes such infections, we often find bacterial secondary infection associated with it.
As it is already past 3 days since his first symptoms, a course of antibiotic might be needed.
Off colour and smelly urine indicates that your son is passing concentrated urine. It is a common association during an active infection. It would settle down slowly.
You are doing the right thing by feeding him with plenty of fluids. In addition I also recommend you to take him to a local doctor / pediatrician
who can start him on oral antibiotics
such as pencillin or cephalosporin
group of drugs. Antihistamine and steam inhalation will also benefit him.
Hope this helps.
I wish your son a speedy recovery.