Your child is suffering from Gastroenteritis- which is most commonly viral in this age.
For vomiting, Domperidone
(Domstal) will be very safe in this age group. You may give him 0.3 mg/kg/dose, and repeat it every 8 hours.
For fever, you can give Calpol. Check the strength of Paracetamol
in it. Dosage is 15mg/kg/dose of Paracetamol, repeated every 6 hours.
You can`t stop his loose stools immediately. But you have to be sure that his fluid intake is adequate. Else he might go in for dehydration
Give him lot of fluids like porridge/ vegetable soups/ ORS/ plain water etc.
Give him curd- it is very good for loose stools as it has probiotic
bacteria naturally. Do not be under false impression that curd causes cold.
Be sure he passes urine frequently- atleast 4 times in a 12 hour period.
Do see your Pediatrician
, who might prescribe probiotic sachets too.
Hope my answer helps you.
Wish a speedy recovery for your son.