First, here is a picture of a normal esophagus. This is looking down toward the LES (the sphincter muscle at the base of the stomach that controls the emptying of the esophagus into the stomach) It is like looking down a tube slide, basically.
And then there is Angela's esophagus! These were taken almost 4 years ago, and the GI doctor at Mayo assumes things have gotten much worse since then. This first picture is from the very top. That is NOT the base of her esophagus (that closed part) but only about 2 inches down.
You have to look at this one sideways, but this is what happens to her esophagus when she lays flat. It completely collapses. It was this picture that landed her sleeping in a hospital bed for the rest of her life. The GI so NO peristalsis AT ALL while he was in there. Peristalsis is the contractions the esophagus makes to move food down to the stomach. Think of the way a snake's body moves, and that is somewhat similar to the way peristalsis movements work.