Bloating

Most cases of stomach bloating are due to improper diet. Gas occurs because of the bacteria in the colon and is a by-product of soluble fiber digestion. Inadequate or irregular intake of fiber and water will cause a person to experience bloating or constipation. The most common natural sources of fiber include fruits and vegetables as well as wheat or oat bran. These fibers are most likely to cause flatulence.[29] Fiber is made by plants and is not easily digested by the human gastrointestinal tract. There are two main types of dietary fiber: soluble and insoluble fiber. Soluble fiber is prebiotic and readily fermented in the colon into gases, while insoluble fiber is metabolically inert and absorbs water as it moves through the digestive system, aiding in defecation. Most types of fiber (insoluble) are attached to body water in the intestine and increase the volume of stools.

Gas in the gastrointestinal tract has only two sources. It is either swallowed air or is produced by bacteria that normally inhabit the intestines, primarily the colon.[30]

Belching or burping is a universal ability that works by removing gas from the stomach through the mouth. The stomach can become bloated when too much air is swallowed during eating and drinking too quickly. As the stomach swells, belching removes the gas and alleviates the pain associated with it. Burping can also be used as a form of relief from abdominal discomfort other than too much gas in the stomach.

Flatulence, or farting, provides relief of much the same kind as burping, but involves the passage of gas from the body via the anus, not the mouth. Bacteria present in the intestinal tract cause gas that is expelled from the anus. They produce the gas as food is digested and moved from the small intestine. This gas builds up and causes swelling or bloating in the abdominal area before it is released.

A common gastrointestinal problem is constipation—infrequent bowel movements, hard stools, or strain during the movements—which causes serious cases of bloating. Since most cases of constipation are temporary, simple lifestyle changes, such as getting more exercise and increasing one's intake of fiber, can contribute to alleviating constipation.[31] Some cases of constipation will continue to worsen and require unconventional methods to release the feces and reduce the amount of stomach bloating. Blood in the stool, intense pain in the abdomen, rectal pain, unexplained weight loss, and continued bloating and constipation not relieved by the above lifestyle changes should be reported to a doctor. Bloating consistently accompanies constipation, and they will not develop without an underlying cause.[22]

Painful burning sensations in the chest that are caused by gastroesophageal reflux is known as heartburn. Reflux is the backflow of gastric acid juices from the stomach into the oesophagus.[32] Heartburn has different triggers, including certain foods, medications, obesity, and stress. These triggers are different for each individual. Gastroesophageal reflux disease or GERD is a chronic condition that can lead to more serious complications like esophageal cancer.[33] Treatment options are available to treat the symptoms and the condition, but there is no cure for the disease. Symptoms include burping, abdominal and stomach bloating, along with pain and discomfort. Heavy meals, lying down or bending over after eating should be avoided to help prevent reflux from occurring. The stomach bloating experienced with reflux is intense and will remain until the food is digested all the way.

Postmortem bloating occurs in cadavers, due to the formation of gases by bacterial action and putrefaction of the internal tissues of the abdomen and the inside of the intestines.[34]

Conditions that are related to bloating include constipation, lactose intolerance, and acid reflux disease.[32] All of these conditions share the same symptoms and can share the same causative agents. These causes include unhealthy diet, smoking, alcohol consumption, low amount of exercise, and overall health. Each of these conditions can be experienced as a symptom of the others and is also a cause for each of them. In most cases where one of the conditions is present, there is at least one if not two of the others. Treatment for each condition is performed using the same medications and recommended dietary changes like increased fiber intake and reduced fat intake. If the conditions develop into diseases such as gastroesophageal reflux disease or chronic constipation, additional medications will be required. Bloating and flatulence are sometimes related to constipation, and treating the underlying condition may be helpful.[35]

Promising evidence on the potential efficacy of the low-FODMAP diet in functional abdominal bloating is provided by the reduction of the bloating which has been observed in some studies on patients with irritable bowel syndrome. Regarding the gluten-free diet, there is insufficient scientific evidence to recommend it to reduce bloating and abdominal distension.[36] As regards the FODMAP diet, this should be provided by experts in nutrition to reduce the risks associated with elimination diets.[37]

There are many over-the-counter (OTC) medications that can be used to treat bloating. Food enzymes can be found in some products that will help break down the sugars found in grains, vegetables and dairy products. They can be taken before food is consumed or added to the food that causes the gas and bloating. The most common treatment is antacids. These medications have no effect on the gas that is present in the intestines but enable gas build-up to be belched away more easily, reducing the amount of bloating that develops. Another treatment is simethicone, an oral anti-foaming agent that helps the body to expel the gas more quickly. Combinations of prokinetics, such as domperidone + metoclopramide + diphenhydramine (the latter for the prevention of extrapyramidal reactions, especially acute dystonic reactions) + proton pump inhibitors (PPIs), have dramatic effects on bloaters and belchers especially.