Thank you for your query.
is not due to Bactrim
syrup. There must be some other cause for it.
There must have been some mistake in the prescription of the dosage. As the weight of the child is not known the dose should have been around 10-12.5 ml. 12 hourly. It will be better to recheck with the doctor. As mentioned earlier the vomiting and diarrhoea is not because of Bactrim.
I hope I have answered your query to your satisfaction.