I could be wrong, but I believe the thinking behind the solids for relux is that it's 'heavier' and will sit down more in their stomachs, holding the stomach acid down instead of it coming back up. DD had reflux from about 3 weeks and just grew out of it at about 8 weeks I think. I cut out acidic foods and dairy and that really seemed to help ease things, no idea if that was a placebo though I know for some babies it goes on a lot longer and is a lot more severe too.