dear son use to 'merlion' when he was at your baby's age. he merlioned at least 3x per day and pediatrician admitted him into hospital for thorough check. everything turned out to be okay. before admitting hospital, pediatrician asked us to change his FM to friso comfort, it is for reflux/constipation/colic... and also under medication. but after 1 week, things not only didnt improve but worsen.
if you think your baby is vomiting too many times and everytime is 'merlion' type, better bring him to a pediatrician. =)