What Causes Flatulence Odor?
Gas is primarily composed of carbon dioxide, oxygen, nitrogen, hydrogen, and sometimes methane. Flatus, gas passed through the anus, may also contain small amounts of gasses containing sulfur. Flatus that contains more sulfur gasses has more odor.
Foods that are known to contribute to flatulence odor include but are not limited to:
(Source: National Institute of Diabetes and Digestive Kidney Diseases, National Institutes of Health)