What would happen when astronauts burp in space? - 2

According to http://www.einsteinyear.org/facts/physicsFacts/

Do astronauts burp? Because you are weightless in space, the contents of your stomach float and tend to stay at the top of your stomach, under the rib cage and close to the valve at the top of your stomach. Because this valve isn't a complete closure (just a muscle that works with gravity), if you burp, it becomes a wet burp from the contents in your stomach. Gross!

The question I initially want to ask was: Do astronaut fart in space? Explain.

But I think this will be too engaging... Plus, does anyone know the answer? I remember I've heard that they won't because the gas cannot be separated due to *no* gravity.