my 3.5 year old daughter poops once in 3 days and it becomes very difficult for her as the stool becomes hard. she takes in good amount of fluid, but still passes stool once in 3-4 days.

A. it is very com in kids. Hard stool is very common in babies ; due to low fiber and water intake . So increase the quantity for water and fiber . Also lactulose can be used if severe constipation is there and it is trouble some .