Hello again, apologies for not posting for a while with an update.
Alas, after the initial improvement with gaviscon, she began screaming again a few days ago and so I stopped it. Admittedly, I had been giving the gaviscon in every other feed as it was making her constipated for up to 2 days at a time which was causing her pain in itself and she was still refusing bottles with it in.
3 days ago I changed the formula to Hipp organic in case she just doesn't like the taste of aptamil/it doesn't agree with her and I'm willing to try anything at this point.... So far, she's taking more each feed although still screaming and pushing/pulling the bottle, particularly in the afternoons and evenings. BUT, she has now sprouted her 1st 2 teeth so I think that the teething must have been causing her pain when feeding which would coincide with when the screaming starting again a few days ago.
So, to recap, at the moment she's only on hipp organic milk without colief or gaviscon and I've put her on 3 hole teats instead of 2 in case she's been getting frustrated at the time it's taking her to feed. (Still up to an hour to clear 4 oz) If the screaming gets really bad once again, I'll put her back on gaviscon and ask the GP for a referral so she can try an alternative that won't constipate her.
She's had colief in her milk since she was 6 weeks old without much difference. I stopped the colief when started gaviscon. Cranial osteopathy from 1 week to 6 weeks didn't help at all, and the therapist commented that everything seemed aligned as it should be.
I feel terrible for saying it, but I'm beginning to wonder if I just have a really awkward baby as it seems that I've tried everything and nothing seems to improve for very long. She seems to be OK in the mornings and will now usually polish off most of 6 oz when she's hungry, but the rest of the time it's still a real struggle.
I'm keeping a note of what/when she feeds so I can take it to the GP and get a referral. Fingers crossed. Thanks once again for all your suggestions and support x