We didn't start Emily on it automatically either, Katie. She was initially gaining weight and we didn't add the Prevacid until her progress kind of stalled out and we went over some aspects of her past history in more detail and decided to try it. She now takes 15mg of Prevacid twice a day and has gained about 3lbs since then. It's not enough weight to make enough difference in avoiding a g-tube, but more than we saw in the several months before that. So I think it's helping the Creon work better.
I do agree that they should be used on an individual basis, when symptoms warrant them or when enzymes alone don't seem to be working as well as they should be ...since there are definitely varied issues that can cause the need. As far as the 'those with cf don't have reflux', I don't think is true either- some have cultured bugs that are clearly of GI origin and thought to be a result of aspirating gastric juices, which is caused by reflux- and when the reflux is treated, pft's go up and resp symptoms improve. And when Emily was a baby, she didn't have the constant bugs and infections or growth failure she went on to develop starting at about age 3, but the one thing she DID have was reflux.