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The green colored stool tested was positive for the first time and after treatment it reverted back to normal yellow colored. But since again with in 2 days it has been green please get the stools tested and if it shows infection again your baby may need to take injections of antibiotic as your doctor had advised but if there is no infection seen in it the stools can be green due to antibiotic induced diarrhoea
for which your baby may need a probiotic
preparation like Nutrolin-B which is a preparation of vitamins
which the doctor will prescribe in the needed dosage so please consult your doctor again.