Reflux

We think 1KB has reflux - this is what the health visitor has suggested or rather asked me if that was what I thought was wrong. We're going to the GP on Monday although I'm not really expecting much more of a diagnosis. I'm getting the impression that infants and their digestive systems are quite the mystery.
I thought all babies were sick  and perhaps she was just greedy and took too much food. However as time has gone on and we're just not able to extend the two hour period I'm getting more and more resentful. She wouldn't need fed every two hours if she kept hold of some of the food I gave her and didn't throw it all back at me. All over her clothes, soaking numerous bibs and muslins, my clothes and our new carpet. 
I'm now realising that perhaps it isn't normal to lose that much of a feed and her screaming and writhing an hour after being fed is perhaps to do with her stomach churning and not simply that she hates falling asleep.
We've been prescribed infant Gaviscon which we happily started using - after figuring out how the heck to actually give it to a breast fed baby. But she immediately became constipated and the writhing in pain from stomach acid was replaced by straining to fill her nappy. The dosage instructions say that for her weight (luckily she has no problem with her weight gain) she can have 12 sachets a day - we've reduced her dosage to 2 sachets a day and she is still bunged up. We're giving tummy massages and hot baths to try and help her along. The two sachets unfortunately don't seem to be cutting out the vomit so we need to up the dosage.
Hoping the GP might have some advice that isn't simply different medicine to help with the constipation - there is a lot of advice on what you can and can't give babies but in my experience they'll give you plenty of sugar filled medicines. Or maybe we may need to decide which is worst constipation or vomit.