Where is that pesky esophagus?

My older brother Richard went to the hospital a couple of weeks ago because of some stomach pains. The doctors eventually found that he had been bleeding internally and that he had lost a lot of blood. They initially thought he had been bleeding from his esophagus, but they eventually determined it was from his stomach. After a couple of weeks of testing and medicating, Richard is doing fine. He returned home from the hospital yesterday and starts back to work on Monday.

Naturally, there's more to the story. My dad had called me a couple of weeks ago to tell me that Richard was in the hospital. Dad wasn't exactly a scholar in high school, but I'm never really sure when he's yanking my chain or not. When telling me what problems Richard was having, here's how our conversation went.

Dad: They think he's bleeding internally from his esophagus.
Me: Oh.

[pause]

Dad: Where is the esophagus?
Me: It's his throat.
Dad: Oh.

[pause]

I thought it was in his ass.

Me: [chuckling] Uh, no, it's at the other end of the digestive tract.

That's my dad! (Although he does sometimes claim otherwise.)