Flatulence is a buildup of gas in the digestive system that can lead to abdominal discomfort. Most people experience flatulence.
Excessive flatulence can cause discomfort and distress. It often occurs as the result of eating certain foods, but it can be a sign of a more serious condition.
In most cases, a change of diet and lifestyle can help control excessive gas.
Fast facts on flatulence
Here are some key points about flatulence. More detail is in the main article.
- The average human passes wind between 10 and 18 times a day.
- People often pass gas without noticing.
- Healthy gas is harmless and has no odor.
- Lifestyle changes can often reduce flatulence.
- Sometimes, there is an underlying medical condition that needs urgent attention, such as food poisoning or an intestinal blockage.
When we eat, drink or swallow saliva, we also swallow tiny amounts of air.
This swallowed air accumulates in the gut.
The gas within our digestive system consists mainly of nitrogen and oxygen.
When we digest food, gas, mainly in the form of hydrogen, methane, and carbon dioxide, is released.
As the gas builds up, the body may need to eliminate it, either through the mouth, by belching, or by passing wind through the anal passage.
Flatulence often occurs without the person being aware of it. There is no smell, and the amount is tiny. When there is a smell, there are usually small amounts of sulfur gases. If food has not been properly digested, it starts to decompose, releasing sulfur.
Flatulence can be the result of normal bodily processes, or it may stem from a condition that affects the digestive system.
Exogenous sources are those that come from outside. We swallow air when we eat, drink, or swallow saliva, especially when excess saliva is produced, due to nausea or acid reflux.
Endogenous sources are inside the gut. Gas may arise as a by-product of digestion of certain foods, or when foods are not completely digested.
If any food is not digested completely by the stomach or the small intestine, flatulence can occur when it reaches the large intestine.
Why do some foods cause more gas?
Foods that cause flatulence tend to be those high in certain polysaccharides, particularly oligosaccharides, such as inulin. Inulin belongs to a class of dietary fibers known as fructans.
Examples of foods that can worsen flatulence include:
- vegetables such as artichokes, broccoli, leeks, cauliflower, cabbage, garlic, onions, beans, Brussels sprouts, and turnips
- cereals, such as wheat or oats
- pulses, including beans and lentils
- dairy produce
- yeast in baked products, such as bread
Here are some reasons why some foods cause more gas, but there are others.
Beans: Complex carbohydrates in beans are difficult for humans to digest. They are digested by microorganisms in the gut known as gut flora, which produce methane. When the complex carbohydrates reach the lower intestine, bacteria feed on them and produce gas.
Lactose intolerance: When people consume food that contains lactose, such as milk, and lack the enzymes to break it down, the bacteria feed on the lactose. In some people, this produces large amounts of gas.
Celiac disease: Intolerance to the protein gluten means that some people have excessive flatulence when they consume barley, wheat, and rye.
Artificial sweeteners: Sorbitol and mannitol are found in candies, chewing-gums, and sugar-free sweet foods. Some people develop diarrhea, gas or both when they consume these substances.
Fiber supplements: Adding these too rapidly to the diet can cause flatulence, especially if they contain psyllium.
Carbonated drinks: Fizzy drinks and beer may cause a build-up of gas in the intestinal tract.
Anyone who is concerned about how their diet may be causing flatulence should ask a doctor or a qualified dietitian for advice.
Conditions that can worsen flatulence
Underlying health conditions: Some chronic conditions can cause flatulence, for example, Crohn's disease, ulcerative colitis, or diverticulitis. Some types of cancer can lead to a blockage in the intestines. Anyone who experiences a sudden or worsening increase in flatulence should see a doctor.
Gallbladder problems: Gallstones and cholecystitis can cause additional gas.
Constipation: Feces can make it harder to expel excess gas, resulting in further accumulation and discomfort.
Gastroenteritis and other intestinal infections: A viral, bacterial, or parasitic infection of the digestive system, or food poisoning, can cause a buildup of gas. Examples include Escherichia coli (E. coli) infection, amebiasis, and giardiasis.
Antibiotics: These can upset the normal intestinal flora, or bacterial flora, in the gut, leading to flatulence.
Laxatives: Regular and excessive use of laxatives can increase the risk of developing flatulence.
If there are signs of poisoning or a blockage, or if there is blood in the feces, urgent medical attention is needed.
Flatulence is not usually a serious problem. In most cases, a change in lifestyle and diet is all that is needed.
Diet and digestion
Flatulence can be avoided by not eating foods that are likely to cause it, such as those containing high levels of carbohydrates that cannot be absorbed.
Foods containing carbohydrates that are easier to digest include:
- citrus fruits
- yogurt, but people who are lactose intolerant should check with a nutritionist
Remember, if you cut out certain foods, you need to make sure that what is left can meet your daily nutritional requirements.
Other ways to reduce flatulence include:
Eating smaller meals: Symptoms often improve if the person eats four to six smaller meals each day, rather than three large ones. Peppermint tea may help.
Eating slowly: Digestion starts in your mouth, so food should be chewed thoroughly before swallowing.
Avoiding gum and carbonated drinks: Chewing gum makes people swallow more air. This can increase flatulence.
Not smoking: Smoking causes people to swallow more air, and it can also irritate the digestive system.
Choosing low-lactose dairy products: Eliminating foods high in lactose may improve symptoms.
Choosing beans that are fermented before cooking: These have less soluble fiber and a higher nutritional content and may decrease flatulence.
Doing exercise: Activity enhances the functioning of the digestive system, and this can help reduce gas and bloating.
Charcoal pads: Placed inside clothing, these absorb released gas and reduce the impact of foul-smelling gas. These are available to purchase online.
If lifestyle and dietary changes are not enough to remove flatulence, over-the-counter (OTC) medications may help.
Charcoal tablets are available at pharmacies and online. Charcoal absorbs gas in your gut, and reduces the symptoms of flatulence.
Anyone on existing medications should first check with their physician, because charcoal may also absorb some of the active ingredients. Not all health professionals recommend using charcoal, as the benefit is unclear.
Persistent pain and discomfort, social embarrassment, and stress are the main complications of flatulence.
However, it may be a good idea to seek advice if:
- excess amounts of gas accumulate
- flatulence occurs frequently
- symptoms start to become more severe
- gas is often released involuntarily
- there is a consistently foul smell
- additional symptoms indicate a possible underlying digestive condition
- sharp, jabbing pains, or cramps, occur in the abdomen, and the pains change places
- there is a bloated feeling or knotted sensation in the abdomen
Severe and persistent flatulence can be a sign of an underlying condition, such as irritable bowel syndrome (IBS).
A doctor can help discover the underlying cause of flatulence and suggest ways to relieve symptoms.
They will ask the patient about their medical history and dietary habits and carry out a physical exam to determine whether there is any distension in the abdomen. They may check for gas by tapping the abdomen and listening for a hollow sound.
They may ask about bowel movements, whether there is any straining when passing a stool, whether there is abdominal pain after meals, and how long the flatulence has lasted.
This can help decide whether the patient might have a condition that needs treatment.
It may help to keep a food diary for a while before visiting the doctor.