Q I am a 20-year-old woman who exercises regularly and eats healthily.
However, even though I move my bowels daily, I still release foul-smelling gas during the day. I have even avoided eating beans and onions, as I have read that they may cause foul-smelling gas.
How can I get rid of or reduce this smell?
A Gas released from the anus, or flatus, is part of normal human function.
However, excessive gas or flatulence can be socially disabling, particularly if the gas smells bad.
Intestinal gas forms when carbohydrates are converted by bacteria in the large intestine, through a chemical reaction known as fermentation. In most instances, hydrogen, an odourless gas, is produced.
However, depending on the type of bacteria present in the large intestine, a foul-smelling gas, methane, may also be produced.
Therefore, intestinal gas production depends on the type of food consumed and the type of bacteria present in the intestines.
Some foods contain carbohydrates which are poorly absorbed and, therefore, are available for fermentation by bacteria in the large intestine.
These are called fermentable carbohydrates, and they include beans and onions. Other common food are apples, milk and garlic.
A recently introduced dietary intervention called the low fermentable, oligo-, di- and mono-saccharides and polyols (Fodmap) diet may be a useful treatment option for you.
In this method, the person will first have to eliminate highly fermentable carbohydrates from his diet. Then, the various types of fermentable carbohydrates (as described in the Fodmap diet) will be reintroduced, one by one, into the person's diet to test for his tolerance to each type. The results will then help in tailoring a diet for each individual.
Studies in Australia and Britain showed that 75 per cent to 80 per cent of patients who underwent this process experienced improvements.
Bacteria, which is present in the normal intestinal tract, is important for normal human function. But the type of intestinal bacteria is complex and unique to each person, which explains why different people respond differently to the same type of food.
Changing these bacteria has been identified as a way to manage intestinal disorders.
The use of healthy bacteria or probiotics is one such strategy, which aims to populate the intestines with healthy bacteria. It has been shown to be effective in reducing symptoms related to intestinal gas.
However, it is still unclear exactly which types of probiotics to use, and how much.
While embarrassing, passing gas is normal. However, excessive and pungent gas may also signal a more serious disease, especially if the person also experiences "alarm symptoms" such as unintended weight loss or blood in his stool.
When in doubt, seek medical advice.
Dr Wang Yu Tien, consultant at the department of gastroenterology and hepatology at Singapore General Hospital
This article was first published on June 12, 2014.
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