Severe costipation in a toddler

A case of severe constipation in a 2 year old child. She would cry a lot while passing stool. She was given nux vomica by another homeopathic doctor which helped her a little bit but later had no effect.

When I saw her I asked whether she was fed formula milk to which the mother said yes. We gave her lac defloratum 1m 2 drops once a day. The next day itself the child passed stools 3-4 times without crying and after a long time slept for 3 hours at a stretch. She now passes stool daily without crying.

The only complain is now that her stool is still very dry and there is lot of thirst (which was always there) to which the mother says that she needs to hide her water bottle sometimes. She is a very amicable child. So will be adding Nat mur.