What are the causes of sulfur-smelling flatulence?

Flatulence, also known as "gas," is experienced by all humans and eliminated by either belching or being passed through the rectum. Sulphur-smelling flatulence refers to hydrogen sulphide (H2S), originating from proteins that contain sulphur.


Gas in the large intestine is mixed with oxygen and nitrogen from either inhaled or swallowed air. Gas molecules consist of hydrogen, carbon dioxide and sometimes methane, which is produced by bacteria in the large intestine while undigested food is being processed, that later reaches the colon.

Intestinal Gas Compounds

In general, humans produce one to three pints of intestinal gas in the colon over a 24-hour period, causing gas to be passed up to 12 times daily.


Intestinal bacteria may cause small amounts of sulphur-containing gases that later become foul-smelling.

Food Consumed

Sugar, starches and fibrous foods like legumes, dairy products, certain vegetables, prunes, apples, wheat products and fatty, fried foods and meats can contribute to sulphur-smelling intestinal gas.

Stomach Disorders

Gastric disturbances and digestive problems such as nutrient malabsorption, gastroenteritis, gastroparesis, lactose intolerance, gut fermentation, irritable bowel syndrome and bowel obstruction can also cause sulphur-smelling flatulence.