When we swallow air when we eat or drink, we release most of it as a burp. Any remaining gas will go in to the large intestine or colon, where bacteria are already working on breaking down undigested food - a process which also produces gas. It all eventually comes out as flatulence.
Wind can be caused by eating too fast, which leads us to gulp down air, or by drinking fizzy drinks or eating when stressed. Wearing tight clothing around the waist can contribute to the problem, as can any change to your diet, for example going abroad.
Not everyone reacts in the same way to the foods or drinks they consume, but these are the most common culprits: