Vomiting — forcefully expelling what’s in your stomach through your mouth — is your body’s way of getting rid of something harmful in the stomach. It may also be a response to irritation in the gut.

Dear Dr. Gott: I am 85 years old. I had my first hip-replacement surgery in spring 2001. While I was in the hospital recovering, I had had my first so-called "episode," for lack of a better word. I ...