It can be a rather disconcerting process but on the whole there is nothing to be concerned about.
This is not to be mistaken with throwing up a little bit in your mouth as this is not an unpleasant experience, rather it can be quite enjoyable!
Pete: "Hey don't worry Steve, you just did what is commonly known as a regurgiburp! Enjoy the ride dude!"
Steve: "... if you say so! You have issues!"
Pete: "Dude, its natural!"