My DD is 8 weeks old & formula fed. During the first 6 weeks of her little life she was struggling with colic/silent reflux. We tried everything you could think of to make her feel better.
At her 6 week check I mentioned this to our usual GP & that I was thinking of swapping her formula to SMA comfort (we used SMA first stage to start). He agreed this was a good idea but she may become constipated & if that was the case to come back and he'll prescribe baby gaviscon.
That night we changed to comfort and everything was fine. DD was happier, feeding well, sleeping well etc. Until late last week when she started straining multiple times a day and nothing coming of it. Sunday morning she strained and the tiniest amount of poop came out. Sunday night she did a 'rabbit dropping' and same again this morning. She hadn't been for a no. 2 for 4 days.
I rang the doctors to book her in to discuss the constipation, then two hours before her appointment she did a normal poop!!!! 
I still went to the appointment and I had a different GP as mine is on AL. I told him everything from the beginning and he's recommended I change her back to the first stage SMA and if her colic/silent reflux returns he'll prescribe baby gaviscon. So I told him my GP was going to prescribe that for the constipation.
So I don't know what to do now!
Does anybody use gaviscon for their little one? Should I wait for my usual GP to be back? Should I change her back to first stage even though she's happier on comfort? Was she not actually constipated?
I absolutely hate times like this when I feel completely out of my depth and useless, so please be kind