E.,
My son is 4 and for most of his life from 2 1/2 until just before he turned 4 he was on some type of allergy medicine, including two prescriptions and one that had steriods in it. I am not a big medicine proponent and believe in natural medicine if it can help. I went the traditional route for a long time and wish I had done what I did sooner.
My son's symptoms weren't always colds, but he was constantly stuffy, didn't eat well and had difficulties sleeping - in the end he was developing sleep apnea.
I finally took him to a doctor who looked at him from a homeopathic standpoint because I didn't know what else to do. They did some allergy testing and then I followed up with an ENT (Ear, Nose and Throat Doctor). I REALLY wish I would have seen the ENT much sooner - my son's adenoids and tonsils were so huge! When he would get colds our regular doctor kept telling me that kids have bigger tonsils anyway, so I just kept on with the medication.
The tonsils were removed on 12/31 and what a different kid I have - he eats better, sleeps better, etc.
You son may be too young for this type of problem but could have some allergy issues and if you aren't happy with what your doctor is telling you maybe you need another opinion from an ENT or someone else...
Trust your instincts to get him help - when he's miserable so are you...
D.