Weight Loss Surgeon

What’s behind the smelly farts after bariatric surgery?
- Dr. Ravi Rao
- March 4, 2024
Many people notice a difference in gas and related smelly farts after bariatric surgery. While most patients might not have any problem, for some, smelly flatulence can be a challenge. Before we look at how to go about the smelly farts after bariatric surgery, let us understand the science behind it.
Changes in the gastrointestinal tract – Bariatric surgery alters the anatomy of the digestive tract. With reduced stomach capacity and altered digestion, the food that enters the body is broken down and absorbed differently. Additionally, depending on the type of bariatric surgery performed, changes in bile flow, enzyme production, and gastric acid secretion may occur. These changes can impact digestion and fermentation of food leading to production of smelly gases.
Dietary changes – The dietary changes after bariatric surgery include more protein and lesser carbohydrate intake. Protein-rich foods especially those high in Sulphur (containing amino acids) such as eggs, meat, dairy can contribute to foul-smelling gases like hydrogen sulfide and methane, during digestion.
Slower digestion and malabsorption – Some bariatric procedures can cause delayed gastric emptying and slower passage time through the tract. This can slow down the fermentation process of undigested food in the intestine, giving more time for production of smelly gases. Sometimes, malabsorption of nutrients, especially from fats and carbohydrates can lead to undigested food reaching the colon, which provides the surface for bacterial fermentation and gas production.
Changes in gut microbiome – The gut microbiome is a diverse community of microorganisms present in the gastrointestinal tract, primarily the colon/large intestine. It plays a crucial role in digestion, metabolism, and immune function. Changes in gut microbiome can lead to increased fermentation and undigested food in the colon resulting in gases with strong odors.
Managing smelly flatulence after bariatric surgery involves strategic planning of the diet.
Research about foods that can increase flatulence such as sugary foods, processed foods, high-fat recipes or greasy foods. Follow a balanced diet with whole grains, lean protein, fruits, vegetables and healthy fats.
Chew the food thoroughly which will reduce the amount of undigested food reaching the colon and contributing to gas production.
Although fiber is essential for digestive health, too much fiber can lead to excessive gas production. So, monitor your fiber intake carefully and increase it gradually.
Include probiotic and prebiotic foods in your diet such as banana, onion, garlic, yogurt, asparagus, etc., and discuss some of the supplement options like Life-Space Probiotics with your doctor.
Stay hydrated and avoid carbonated beverages.
Some medications are known to reduce odor and improve quality of life. Talk to your doctor about these options.
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