Paediatrics symptoms and conditions

i'm a mother of 1yr 8mths son. my son gets flu n cough about once every month. we went to this doctor that practiced phlegm suction (because babies have phlegm in their bodies). but since he knows how to reject the tube into his mouth, we think we can try another doctor. so we went to see a specialist. after telling her the history of our son, she came into a conclusion that our son has a mild asthma. then she prescribed a ventolin and singulair. the stock is only for 2weeks then we shall continue the medication for 2months. he shows very positive effects- easily sleep (which is very rare except he gets too tired), sleep soundly and gets better quickly. until recently he got high fever and we went to the regular doctor. he said it is not good to feed the baby with the medicine that heals cough quickly because the phlegm won't got out. then we stopped the singulair. when the fever gets higher and shaking, he's admitted. there at the paediatrics we got another opinion saying that early stage of asthma we don't use the singulair. they said, besides expensive it also not appropriate for the kids. though our son got admitted but luckily we got very useful information from the trustful sources! as for our son, he acts like so active like never before. i'm not sure it is because of the side effects or kids are like that..
just 1 thing i don't understand, why people that called themselves paediatricians, children's specialist, don't really know what's best for the kids..what a pity..i think they should read more..