For most of my life, I was extremely skeptical of homeopathy. Even now, and even after meeting with research scientists like the late Jacques Benveniste, I can't say I really understand how homeopathy works. Moreover, classical homeopathy was as much about finding emotional causes of illness as in dispensing quick treatments for disease.
Nonetheless, homeopathy often works, has no side effects, is compatible with medical treatment, and is widely available outside the USA. Some common homeopathic remedies for chronic flatulence include:
Arsenicum album relieves flatulance accompanying mild cases of stomach upset after eating spoiled food.
Carbo vegetalis is used for flatulence that's accompanied by belching.
Colocynthis treats flatulence that's triggered by torsion, that is, a sudden pop of gas when standing up, rolling over, stretching, etc.
Lycopodium for flatulence accompanying bloating and constipation. Traditional homeopathy suggests that this remedy works best for people who are taking on too many responsibilities with too little help.
Natrium Sulphuricum is really more of a liver remedy, but it's also used when there is flatulence and a bitter taste in the mouth.
And, Sulfur (the homeopathic remedy, not the yellow mineral) treats strongly odorous flatulence. There are, of course, many other remedies.
Most homeopaths recommend you take a single dose of the appropriate preparation and wait to see what happens. If it works, just let your body's natural healing processes take over until you feel the need for another dose, usually a few hours to about a day. If it does not work, simply choose another remedy.