Smelly farts are mainly caused by the foods eaten and how they are digested, with sulfur-containing foods playing a big role. Foods high in fiber, especially certain vegetables like broccoli, cabbage, and asparagus, contain sulfur, which produces gases like hydrogen sulfide that smell like rotten eggs. Food intolerances, such as lactose intolerance and celiac disease, can also cause foul-smelling gas because undigested food ferments in the gut. Other causes include medications that disrupt gut bacteria, constipation which allows gas to build up, bacterial infections in the digestive tract, and in rare cases, conditions like colon cancer. Changes in gut bacteria balance can also make gas smell worse.
Main Causes of Smelly Farts
- High-fiber foods: Slow digestion and sulfur compounds in vegetables like broccoli and cabbage produce smelly gas.
- Food intolerances: Lactose intolerance and celiac disease cause fermentation of undigested food, resulting in odor.
- Medications: Antibiotics and others can disrupt gut bacteria leading to smelly gas.
- Constipation: Gas buildup due to stool staying too long in the colon increases odor.
- Bacterial infections and imbalances: Overgrowth of bacteria that produce sulfur compounds.
- Rare causes: Colon cancer or other digestive tract issues causing blockages and gas buildup.
Foods That Cause Smelly Gas
- Cruciferous vegetables (broccoli, cabbage, Brussels sprouts)
- Beans and legumes
- Dairy products (if lactose intolerant)
- High-protein meats (turkey, beef)
- Eggs, garlic, onions, and other sulfur-rich foods
Adjusting diet and addressing any underlying health conditions can reduce smelly flatulence. If symptoms persist or worsen, consulting a healthcare professional is advisable.
