It's fine if your child doesn't pass stools for 2-3 days.
But use a stool softener for a month atleast.
As i don't know your baby s age i can't comment on medications but constipation is very common on weaning and in summers.
You need to consult a Pediatrician if there's vomiting, abdominal distension or delayed development.
Next Steps
USG Abdomen
Thyroid profile
Health Tips
Stop hematinics (iron supplements ) and
calcium supplements. They are notorious to cause constipation !!