Flatulence is the presence of gas under some degree of pressure, in a confined space. The term is normally used of the presence of gas in the digestive tract of mammals. However, a balloon is flatulent as is a fizzy drink until the gas is released by opening the bottle containing it.  Though confused by the word's use as a euphemism for 'fart', flatulence is distinct from flatus, which is the release of such confined gas.  The distinction becomes very important in cases of bloat. In the animal digestive tract, the gas is produced by symbiotic bacteria and yeasts....
Flātus is a Latin word meaning a puff or blowing of a gas such as air. Flatulence is a French noun derived from flātus, which as a medical term means 'accumulation of gas in a natural cavity'.  More generally, flatulent means 'of a windy nature' or 'full of air and wind'. By extension, foods such as beans may be called 'flatulent', as they generate gas in the digestive tract which then becomes flatulent as it is liable to produce flātūs - puffs, blows and breathing, via the œsophagus (gullet) and mouth or via the anus. Flatulence is therefore a tendency to produce puffs and blows so the word can be applied to the character of a haughty person or to the wolf of the Three Little Pigs story, as well as to the more usual use in alluding to a physiological tendency to break wind.
'Meteorism' is a near-synonym of flatulence in the medical sense. However, it may arise from a blockage which prevents the escape of gas. It is therefore not strictly, a synonym. It is derived from Greek rather than Latin. It will have influenced English by way of the writings of Hippocrates, whose works were long a major influence on the thought of western medical doctors. It is a 'flatulent distension of the abdomen with gas in the alimentary canal' , and is used as a synonym of bloat in veterinary use. The Greek original, μετεωρισμοσ (meteorismos), means 'being raised up, swelling'  alternatively, 'elation, excitement of mind'....