Hi. My 3 1/2 year old daughter has been suffering from a horrible mucus cough for 2 months now. I have brought her to the doctors twice and both visits were followed by chest x-rays and found clear. I was told it's viral and to give her children's mucinex but this has not helped. My daughter coughs all day and all night and gages on the mucus causing her to vomit. She is up all night coughing and can not catch her breath inbetween coughs. Please help.