Charcoal comes from the burning of substances such as oil and wood. It is an absorbent, meaning it can bind up other substances, such as chemicals and gases. Charcoal is known to bind certain poisons so it will often be used in acute poisonings. In gastroenterology, it may be helpful in binding methane or sulfide intestinal gases, which are the main offenders in flatus odor.
Some researchers think charcoal reduces intestinal gas.
Other studies contradict this claim. Still, since charcoal is generally harmless, it can be tried for this purpose. Belching and bloating comes mostly from swallowed air. Charcoal has no effect on these conditions. Follow your physician's instructions carefully.