Hi, I need some advice. My 7 week old baby is currently on aptamil 1 but is suffering constipation 1/2 times each week. My doctor has given lactulose to give him as and when but I was wondering if it might he his milk thats causing it, and if I should try swapping him to see? If so, does anyone have any recommendations for what brand to try? As I have been told aptamil is the best. Thanks.