お腹にガスがたまっています。

stomach

at (place, time); in; on; during; to (direction, state); toward; into; for (purpose); because of (reason); for; with; by; from; as (i.e. in the role of); per; in; for; a (e.g. "once a month"); and; in addition to; if; although

gas (state of matter, e.g. poison gas, natural gas); gasoline; gas; petrol; dense fog; thick fog; gas stove; gas cooker; gas range; flatulence; gas; wind; fart

indicates sentence subject (occasionally object); indicates possessive (esp. in literary expressions); but; however; still; and

to bear (often adds emphasis); to endure