I can promise you that a few times your body released gas on its own whether or not you were aware of it. I don't mean it in a bad way it's just what the human body does
After all we breath in oxygen and release CO...
https://youtu.be/GgVQOSxlUV0?feature=shared
https://youtu.be/5Wf7tiB6WzQ?feature=shared See youtube link