Dr. Greene's Answer
With my first child I had to change shirts several times a day, he spit up so often. For kids who spit up, the average time to outgrow messy episodes is 7 months. I’m glad your daughter was tested to find out what was going on.
The delay in moving material through the stomach can either be from slow or disordered waves of contraction (these normally propel contents through) or from something blocking the drain out of the stomach (called a gastric outlet obstruction).
Gastric outlet obstruction can be caused by a pyloric valve (the valve at the bottom of the stomach) that is too muscular or too thick. It can also be caused by ulcers or webs or foreign bodies or inflammation. Occasionally, an outlet obstruction needs to be fixed surgically.
There are medicines, such as Reglan, that can speed gastric emptying in many kids. And for some children, smaller, more frequent feedings are all that are necessary.
You’ll know much more about what is (or is not) causing this for your child after the next tests. Whatever turns up, it sounds like you are on the road toward identifying and addressing whatever has been stopping her food from traveling smoothly down and through.