Meteorism

Etiology

The causes of meteorism are usually benign, such as swallowing too much air while eating or excessive fermentation caused by intestinal flora bacteria. More concerning causes may include bowel obstruction, renal stones, functional disorder, overeating, bacterial overgrowth, inflammation of the bowel, blunt kidney trauma, peritonitis, and idiopathic causes. Canon of Medicine, authored by Avicenna, is one of the most prominent medical manuscripts, touching on gastrointestinal disorders such as flatulence. From Avicenna's viewpoint, bloating results from imperfect digestion caused by 4 eating habits, including consumption of beans/peas, consumption of fruits, consumption of smoked salted foods, and overeating.[2] Certain fruits and vegetables contain large amounts of fructose and oligosaccharides that can promote excessive gas. 

Epidemiology

Meteorism is a very common symptom that occurs in people of all ages. It is equally prevalent in all races and can affect infants as well as the elderly. The majority of people present with meteorism in the third decade of life. About 15% to 23% of Asians and 15% to 30% of Americans suffer from flatulence.[3]

Pathophysiology

Common Causes of Meteorism

Functional

In most people, the cause of meteorism is unknown. These individuals present in the third decade of life with complaints of belching, excess gas, bloated sensation, and abdominal distension. Abdominal x-rays usually reveal a nonspecific collection of gas in the intestine. Workup usually reveals no pathology. X-rays should rule out constipation.[4]

Bowel obstruction

Bowel obstruction from any cause can lead to the accumulation of gas in the intestine. This is pathological, and the patient may present with nausea, vomiting, and an inability to pass gas. X-rays show dilated bowel loops, air-fluid levels, and a lack of air in the distal colon or rectum.

Ileus

Ileus is essentially the disruption of normal propulsive bowel movements. It has many causes, and the failure of peristalsis leads to the accumulation of air in the GI tract. Patients with ileus often present with abdominal distension, moderate abdominal discomfort, bilious vomiting, an absence of bowel movements, and no appetite. Risk factors for ileus include the following:

• Electrolyte imbalance (hypokalemia, hypercalcemia)
• Gastrointestinal surgery
• Diabetes mellitus
• Hypothyroidism
• Use of medications like opiates
• Spinal cord injury

Ileus is managed conservatively by limiting the patient to nothing by mouth and administering fluids. A nasogastric tube may be required to decompress the intestine and stomach. Most patients start to recover within 3 to 5 days. One may use peristaltic agents like erythromycin or metoclopramide to enhance bowel movements.

Irritable bowel syndrome 

Irritable bowel syndrome is a complex disorder of bowel motility that presents with abdominal pain and a changing pattern of bowel movements. Almost universally, patients complain of a bloated sensation. So far, no patient has shown any underlying damage to the bowel with IBS. The disorder presents with vague abdominal symptoms in the third decade of life. The disorder may be associated with diarrhea, constipation, or a combination of symptoms. 

IBS seriously affects the quality of life and results in missed work and school. These patients are not able to tolerate a wide range of foods. As soon as the offending food is ingested, the patient complains of bloating, abdominal pain, and nausea. Many of these patients also have other existing disorders like major depression, anxiety, and fibromyalgia. 

The diagnosis of IBS is difficult as the signs and symptoms are nonspecific. Investigations are usually done to rule out other organic causes like inflammatory bowel disease, celiac disease, and food intolerance. Unfortunately, there is no cure for IBS, and there is no 1 treatment that works for everyone. Patients are counseled on dietary changes, the use of probiotics, and eating a diet low in fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAP).[5] Patients with recurrent disease may find loperamide helpful, and those with constipation may require laxatives. Antidepressants are known to help improve mood and pain in many patients.

History and Physical

The most common symptom of meteorism is a bloated sensation. It may be associated with abdominal discomfort. Some individuals may also complain of a distended stomach and excessive belching and/or passage of flatus. The sensation of bloating may last a few minutes or for extended periods. Sometimes, the abdominal pain may feel dull or sharp and cause cramping. Often, the pain of bloating can be confused with bowel obstruction, appendicitis, cholecystitis, or peptic ulcer disease. On physical exam, one may note distension of the abdomen and marked tympany on palpation. Auscultation may reveal rumblings, bowel sounds, or tinkling sounds. The rectal exam in these patients is unremarkable.

Evaluation

When patients present with meteorism, the onus is on the healthcare worker to first rule out an organic disorder like inflammatory bowel disease, bowel obstruction, colon cancer, strangulated hernia, or volvulus. The laboratory blood work is chiefly done to rule out other pathologies. Usually, no imaging is necessary to make a diagnosis of meteorism. Still, if the abdominal exam reveals marked tenderness or pain, one should obtain plain X-rays to look for dilated bowel loops, air-fluid levels, or free air. Other tests depend on the presentation and physical exam.

Treatment / Management

Once bloating has been diagnosed, the treatment depends on the cause. For functional bloating, the treatment is supportive. The individual must keep a food diary and note all the symptoms. Any food that produces a bloating sensation must then be eliminated. One of the most common causes of bloating and flatulence is improper eating habits. 

Helpful Suggestions

• Avoiding overeating
  • Limit food intake to 4 to 7 small meals daily rather than 3 large meals.
• Avoid foods that are rich in fat and simple carbohydrates
  • Fats take a lot longer to digest; since they remain in the abdomen a lot longer, the symptoms of bloating may continue for many hours.
  • The low FODMAP diet has been shown to reduce bloating sensation in individuals.
• Avoid eating too fast to prevent swallowing air.
  • Eating slowly is the key but also suppresses the desire to eat more. Foods should be chewed thoroughly.
• Drinking beverages while eating or immediately after should be avoided, as this can promote flatulence in some people
  • Beverages, vegetables, and fruits should be consumed at least 1 hour after food.[6]
• Adding ginger, cumin, and herbs like dill, parsley, and basil may reduce flatulence.[6]
(B3)

To decrease the gassiness, the following is recommended:

• Do not chew gum [7]
• [7]Do not drink fluids through a straw
• Avoid consuming carbonated sodas
• Do not suck on candy
(A1)

Some individuals tend to swallow air when they are anxious or nervous. The best way to avoid this is to relax and reduce stress. One should practice breathing exercises, yoga, or Tai Chi. According to a recent study, patients receiving vitamin D had improved quality of life from bloating compared to patients who did not.[8] Moxibustion used with acupuncture has been shown to reduce bloating sensation.[9] Psychotherapy has also been found to improve the quality of life in patients with functional dyspepsia.[10].(B2)

Foods to Avoid

Certain foods can worsen bloating and cause gassiness, including:

• Lentils and beans contain indigestible sugars, which are broken down by bacteria, resulting in the generation of gas [6]
• Fruits and vegetables like carrots, cabbage, Brussels sprouts, prunes, and apricots also cause gassiness
• Artificial sweeteners like sorbitol are not easy to digest and are broken down by bacteria to produce gas.
• Patients with meteorism should avoid dairy products, as they can worsen the bloating sensation.
• Wheat contains a protein called gluten, which may cause bloating.[11] Gluten should be included in the elimination diet to rule out gluten sensitivity.
(B3)

People prone to meteorism should become physically active, as this can also increase peristalsis and empty the intestine of gas.

Differential Diagnosis

The differential diagnoses for meteorism include the following:

• Aerophagia
• Bacterial overgrowth in the small intestine
• Disorder of gastrointestinal transit
• Gastric hypersecretion
• Ingestion of gas-producing foods
• Malabsorption or maldigestion of carbohydrates

Prognosis

Temporary bloating is a mild annoyance that can be relieved by changing diet. However, if the patient has persistent bloating and gassiness, the healthcare provider must rule out an organic cause.