We finally got Tanner to a new doctor yesterday! He had been seeing our family doctor but we were unhappy with his response to Tanner's several problems. The new doctor answered some questions for us and is taking some action!
Since he was born 11 weeks ago, he has always spit up pretty much everything he eats. As a result, Tanner has not gained much weight. Our old doctor just dismissed the spitting up as normal baby spit up, and wasn't bothered by the minimal weight gain because he was gaining weight, even though it was an ounce or so every couple of weeks.
Yesterday, this new doctor told us that Tanner's weight is way off for what he should weigh at his age, and that the spit up issue could be something serious that needs to be corrected. So, they are sending him for some x-ray type stuff to get a good look into his chest, lungs, and tummy and see what's going on. So even though we still don't have any answers, we are happy that it looks like we're on the right road to getting all these issues taken care of!