My little girl is 7 and a half weeks old and h...

My little girl is 7 and a half weeks old and has terrible trouble both pooing and farting. She is constantly pushing and in terrible pain. She is feed on Karikare Sensikare at the moment but it doesn't seem to be working for her. I talked to my MHC nurse who reccommended the Nan as it has bifidus in it which will help to put the good bacteria into her bowel and hopefully keep her regular. But that was the same reason why we put her on the Karikare. We have tried Coloxyl drops and Infacol wind drops but nothing seems to work. I was wondering if anyone is using the Nan and has any advice or tips.