Are there any good remedies to give an 18 month old baby? He's trying to get over a cold.?

Right now he's got a severe cough which makes him gag and throw up. He's too young for cold medications, so were trying to see what would be good to give him to sooth his cough. We already had taken him to a doctor and they said he doesn't have bronchitis, pneumonia, or asthma. Just the cold.