Farts (flatulence) are mainly caused by gas building up in your digestive system, either from swallowed air or from the way your body breaks down food in the gut. This gas is then released through the rectum as a normal part of digestion.

What a fart actually is

  • A fart is a mix of gases like nitrogen, hydrogen, carbon dioxide, methane, and small amounts of sulfur compounds that give it a strong smell.
  • This gas forms as food is digested and as bacteria in your intestines break down what your stomach and small intestine did not fully process.

Main causes of farts

  • Swallowed air : Talking while eating, drinking fast, using straws, chewing gum, smoking, or drinking fizzy drinks all increase swallowed air, which can later come out as farts.
  • Normal digestion of food : When undigested carbohydrates reach the large intestine, gut bacteria ferment them and produce gas.
  • Gas‑producing foods : Beans, lentils, cabbage, broccoli, onions, whole grains, and high‑fiber foods are classic triggers.
  • Sugars and carbs : Lactose (in dairy), fructose (some fruits and sweeteners), and sugar alcohols like sorbitol and mannitol (in “sugar‑free” products) can cause extra gas if they are not well absorbed.

When it’s from a sensitivity or condition

Sometimes extra farting is linked to how your body handles specific foods or a medical issue.

  • Lactose intolerance : Lacking enough lactase enzyme means dairy reaches the colon undigested, where bacteria turn it into gas and cause bloating and diarrhea.
  • Gluten issues (celiac disease) : In people with celiac disease, eating wheat, barley, or rye can inflame the gut and lead to flatulence and other digestive symptoms.
  • Irritable bowel syndrome (IBS) : IBS commonly causes bloating, abdominal pain, and changes in bowel habits along with frequent gas.
  • Other gut conditions : Crohn’s disease, ulcerative colitis, small intestinal bacterial overgrowth (SIBO), infections, constipation, or even bowel obstruction can all increase gas.

Why some farts smell worse

  • Sulfur‑containing foods : Eggs, garlic, onions, and some meats can increase sulfur compounds that make farts especially stinky.
  • Slow transit or constipation : When stool sits longer in the colon, bacteria have more time to ferment and produce stronger‑smelling gas.
  • Underlying disease : Very foul, persistent gas with weight loss, blood in stool, or severe pain can sometimes signal a more serious issue and should be checked by a doctor.

Should you worry about farting?

  • Passing gas 10–20 times a day is usually considered normal and just part of healthy digestion.
  • You should seek medical advice if gas comes with red‑flag signs like unintentional weight loss, persistent abdominal pain, blood in stool, fever, or a big change in bowel habits.

Information gathered from public forums or data available on the internet and portrayed here.