In my 35 years of practice as a pediatrician, I have hardly ever seen an 8 months old baby suffering from Amoebiasis
. However rarely it may occur due to contaminated food or water. You have already given Metronidazole
for 10 days which is quite sufficient. I wonder if you got his stool tested for Ph and reducing substances.Moreover a culture should be done to rule out a bacterial infection. If these tests are reported to be negative you can try a 2 weeks course of Zinc syrup 1/2 a teaspoon twice a day and probiotics like darolac or vibact
which may help in prolonged diarrhoea
. But do consult a pediatrician
if these don't help.