my baby is 6 months old and I have started giving her complimentary feeding..I am giving her boiled Apple puree and boiled carrot puree..she is also taking iron supplement..she is having her motions in two days and she seems to have constipation..she puts a lot of pressure while passing the stool..this has happened from last 2 times..it is her 3rd week of complimentary feeding and iron supplement..from last 3 days she is having Apple puree in the morning and carrot puree in afternoon..before that she was only having carrot puree from last 10-12 days..what might be the reason of her constipation?