There are several natural causes of flatulence. Flatulence can also be caused by some health conditions that are related to the digestive system.
There are three main causes of excessive flatulence. They are:
- swallowing more air than usual
- eating food that is difficult to digest
- having an underlying health condition that affects your digestive system
These are discussed below.
Swallowing air
It is perfectly normal to swallow air while breathing and eating. However, it is easy to swallow a lot more air than usual without realising it. This can lead to symptoms of excessive flatulence. Excess air can be swallowed by:
- chewing gum
- smoking
- sucking on pen tops
- not chewing food slowly and thoroughly (swallowing large pieces of food will result in you swallowing more air)
Hot and fizzy drinks also increase the amount of carbon dioxide in your stomach, although this is more likely to lead to symptoms of belching rather than flatulence.
Food
Much of the food that you eat is carbohydrate. Carbohydrates are made up of long chains of sugar molecules. Some carbohydrates cannot be digested and absorbed by the intestines and pass down into your colon. These are known as unabsorbable carbohydrates.
Your colon contains more than 500 different types of bacteria. The bacteria start to break down the carbohydrates and, in the process, they produce gas, which is released as flatulence.
Foods that contain a high amount of unabsorbable carbohydrates include:
- beans
- broccoli
- cabbage
- cauliflower
- artichokes
- raisins
- pulses
- lentils
- prunes
- apples
- brussels sprouts
Slimming products that contain sorbitol (a sugar substitute) or fructose (a type of sugar) can also cause flatulence because both sorbitol and fructose are unabsorbable carbohydrates. Many fruit juices also contain high levels of fructose.
Many foods that contain unabsorbable carbohydrates are digested over a long period of time. This means that any undigested food will eventually start to decompose. The decomposing food releases a small amount of sulphur gas, which causes the foul smell associated with flatulence.
Health conditions
Health conditions that can cause symptoms of flatulence include:
- constipation
- irritable bowel syndrome (IBS)
- coeliac disease, which is a common digestive condition where a person has an intolerance to a protein called gluten, which is found in wheat, rye and barley
- lactose intolerance, which is where the body is unable to break down lactose (a natural sugar found in milk and dairy products) and cannot absorb it into the blood
- gastroenteritis, which is a stomach and bowel infection
- malabsorption, which is where the intestines are unable to absorb nutrients properly
