You have not mentioned the duration of symptoms. If vomiting
has started recently, then the child is perhaps suffering from acute gastritis
due to viral infection. Incidentally, did you give him ice cream,candy or sweetmeat before the onset of these symptoms? Iron drops or painkiller medicines like brufen too can cause such symptoms.
Give him anti-emetic like domperidone
and some digene liquid. Give only liquids for 1-2 days and withhold solids. However, if the vomiting is frequent, forceful and persists, you must rush to a Pediatrician
for proper treatment.