is there an internal force inside the body of a human being that’s makes him to vomit?

Question: is there an internal force inside the body of a human being that's makes him to vomit?
- Keywords:
  body,
  force,
  human,
  vomit
Asked by absb266 to Charles on 24 Jan 2017.
- Charles Kamau answered on 24 Jan 2017:
  
  you may choose to call it an internal force – but it is mainly a reflex. when irritated or triggered, the vomit nerve tends to contract the stomach walls and open the sphincter hence vomiting.

Question: is there an internal force inside the body of a human being that's makes him to vomit?