Started slowly moving DS from Aptamil to Hipp the day before yesterday. Just 30ml then later 45ml day before yesterday, then one feed (90ml) yesterday. Nice and cautious I thought. Well, last time there was a dirty nappy was yesterday morning. He's now obviously straining but nothing coming. What do I do to help him? Bm normally gives him the runs so trying to give as much of that as there is in the boobs (not endless amounts as that's why we do formula in the first place) and haven't given any formula since 5am. Will have to soon though as he needs to eat more than I have for him.