if the baby does have acid reflux, don't worry about it. Both of my kids, now ages 6 and 22 months has had it, and they outgrow it by the time they are around 9 months old. The only thing besides the Zantac that I did was switched from formula to vitamin d milk. Their dr. thought that they was allergic to dairy also, so I was buying formula that had no dairy in it, formula with cereal added, and many others that cost anywhere from $5.00 a can to $40 a can. The Zantac will not hurt the baby at all, and yes by some unknown reason, they do gain the weight that they need. As for the blockage testing, what they will do there is take the baby, shut you out in the waiting room cause they don't want the parents freaking out on them, strap the baby in a chair,( after you feed it some chalky stuff out of a bottle) and then they spin and flip the baby in every way possible, about like a carnival ride, and see if it throws back up the chalky stuff right away. the test will cost about $800 for about 20 minutes of listening to your kid scream and bawl nonstop cause it doesn;'t know what is going on and it;s head is still spinning for a couple of hours later. Been there and done that. I was only 20 when I had my first, and they didn't inform me of what they was going to do. both me and my hubby freaked out when we heard our daughter scream like that, but they had the door locked so we couldn't get in. Have them do a scope (exploratory) instead. its less nerve wracking.