my baby is 3 yr old.... she has constipation.... she passes hard stool and complaints of stomachache.... she eats fruits, vegetables, roti, rice and drinks 500-600ml of water daily..... she used to drink 2 cups of milk... but because of constipation it was stopped.... she had similar complaints 20 days back.... for which we consultant doctor.... and medication was taken.... now again she has similar complaints..... what could be the cause and what to be done