The human gut normally contains around 200 milliliters (about 7 oz) of gas, although the quantity can fluctuate slightly. Sometimes, there is excessive gas in the gut, which produces a host of signs and symptoms. Excessive gas in the gut may be caused by a variety of reasons, not all of which are pathogenic.
This gas in the gut is normal and comes from the following sources:
- Gas in the gut could be the air that is swallowed during eating and drinking activities. This act of swallowing air is technically known as aerophagia.
- Gas in the gut could also come from ingestion of carbonated beverages such as sodas and colas. A variety of carbonated beverages are common in the modern day diet of people around the world.
- Gas in the gut is also formed by the action of digestive enzymes and intestinal bacteria on the foods that we eat. Breakdown of certain foods causes production of excessive gas.
Most of the gas present in the upper gut is expelled through the mouth via belching. The gas passed out through belching is usually similar in composition to the air. Some gas may pass into the lower gut and get expelled as flatus.
Signs and Symptoms
The following are the most common signs and symptoms of excessive gas in the gut:
- Excessive gas in the upper gut may cause excessive belching or burping.
- Excessive gas in the lower regions of the gut may cause excessive flatulence.
- Excessive gas may also produce a sensation of fullness or pressure in the abdomen (commonly referred to as abdominal bloating).
- Enlargement of the abdomen (also known as abdominal distension) may or may not be present along with abdominal bloating.
Read more on excessive belching.
Some other signs and symptoms that may be present in case of excessive gas in the gut are as follows:
- Cramps in the stomach or intestine may occur. These cramps may result when excessive gas in the gut stretches the walls of the gut and causes reflex contraction and spasm of the smooth muscles present in the walls of the gut.
- Abdominal pain may occur due to distention of the walls of the gut. This mostly happens when the gas gets trapped between the solid matter in the gut and cannot find a way out.
- Rumbling noises in the stomach may be heard as the gas moves through the gut and the contractions of the walls of the gut mix the solid, liquid, and gaseous contents in the gut.
Read more on sulfur burps.
Causes of Excessive Gas in the Gut
The following are some of the main causes of excessive gas in the gut:
Aerophagia (swallowing air) and consumption of carbonated beverages are the most common causes of excessive gas in the upper gut (esophagus, stomach and duodenum). Swallowing of air can occur due to a variety of reasons, such as eating and drinking very rapidly, hyperventilating (such as in anxiety), breathing through the mouth, excessive use of chewing tobacco or gum, and poorly-fitted dentures. The swallowed air is usually trapped in the upper esophagus. Sometimes, it may also find its way down to the stomach and the duodenum. If the air remains in the upper get, it is expelled through belching. If the air reaches the lower gut, then it is expelled through flatus.
Consumption of certain foods results in increased production of gas during the processes of digestion in the gut. The excessive gas produced by these “gassy foods” is expelled from the lower gut as flatus. Examples of foods that can cause excessive production of gas in the gut include beans, lentils, broccoli, brussels sprouts, asparagus and milk. It is important to note that these foods do not produce excessive gas in all individuals. For example, some people can digest milk better than others. Also, the ability to digest foods might change with age.
Helicobacter pylori infection
Infection of the stomach and duodenal mucosa by the bacteria Helicobacter pylori (commonly abbreviated as H. pylori), could also contribute to gas in the stomach. Helicobacter pylori are spiral-shaped bacteria that have a tendency to invade the gastric mucosa.
They have the ability to survive in the highly acidic gastric region by modifying their environment and reducing the acidity. This process leads to the production of small amounts of gas. On its own, gas produced by H. pylori infection may not be excessive. However, it may partly contribute to the presence of excessive gas in the stomach.
Hiatial hernia refers to a condition in which a portion of the upper part of the stomach breaches the diaphragm and enters the thoracic cavity. This abnormal protrusion of the upper part of the stomach into the chest cavity results in a host of symptoms involving the upper gastrointestinal tract. Gas production is not increased by hiatal hernia. However, stomach volume is decreased, leading to problems with digestion, bloating stomach, and excessive belching.
Delayed gastric emptying
Delayed gastric emptying refers to conditions in which the food stays in the stomach for longer than normal duration. This delay in gastric emptying increases production of gas in the stomach due to longer action of stomach acid on the food. Also, delayed gastric emptying allows bacteria (such as H. pylori) to act on the food for a longer duration, resulting in excessive gas production.
The delay in gastric emptying can be caused by various factors, such as dysfunction of the stomach muscles or nerves (such as in gastroparesis), disturbance in digestive hormone production, and physical obstruction to the movement of food through the stomach (such as in pyloric stenosis, stomach polyp and tumors).
Intolerance to foods
Food intolerance and malabsorption of digested products can result in excessive production of gas in the gut. Gas production in these conditions is enhanced due to longer time available for the action of intestinal bacteria on undigested or unabsorbed food in the gut. Examples of food intolerance include lactose intolerance and gluten intolerance. Examples of malabsorption conditions include malabsorption of fructose and sorbitol sugars.
Small intestine bacterial overgrowth
Small intestinal bacterial overgrowth (commonly abbreviated as SIBO) refers to an overgrowth of the normal gut flora in the small intestine. The overgrown bacterial population then acts on the food in the intestine, resulting in production of excessive gas as a byproduct. Small intestinal bacterial overgrowth also impairs normal digestion and absorption processes, leading to malabsorption syndromes and nutrient deficiencies.