Hello,I am so sorry your little one is having trouble.
Canned pumpkin can be used to help relieve constipation. 1-2 tablespoons now and then 1 tablespoon twice daily until stool is produced.
You can also try 1 tablespoon of metamucil, or 3-4 tablespoons of grapenuts cereal.
If she stop eating or is vomiting I would suggest having her seen by a vet. Not passing stool can also be a sign of blockage in the digestive tract.
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I hope this helps and your girl feels better soon. Please reply back if you have additional questions or concerns