Bloating is a sensation of abdominal fullness and a feeling of trapped gas, sometimes with visible abdominal distention. There may also be abdominal discomfort and flatulence. There is a small handful of usual causes, most of which interfere with digestion in one way or another.
First, I will briefly discuss the function of the intestines. The small intestine is responsible for digesting food by breaking it down into smaller molecules, which are then passed through the intestinal lining and into the bloodstream. The small intestine has normally has few bacteria. The large intestine (colon), which is full of bacteria, is responsible for disposal of waste, but also for recycling water back into the system.
Gas-producing foods
Common gas-producing foods include broccoli, brussels sprouts, cabbage, legumes, onions, potatoes, and wheat. Avoid these foods for a week; if your symptoms resolve, then you know that gas-producing foods are to blame. You can then try to add back these foods one at a time, taking careful note of which foods cause symptoms, and which do not.
FODMAPS
Sugars are digested by enzymes on the surface of the small intestine that break down the sugars into smaller molecules, which are then passed through the intestinal membrane into the bloodstream. If you have an enzyme deficiency, or if you consume more sugars than you can digest, the sugars will not be not be digested. Instead, they will pass downstream, where two things can happen: one, the sugars act like an osmotic agent, drawing fluid into the intestine, causing a feeling of fullness, and two, colon bacteria consume the sugars, releasing gas. I once had a patient who suddenly decided to be a vegetarian, after watching a Netflix program on meat. In order to satisfy his appetite, he began to eat a great deal of hummus, and he developed abdominal bloating and flatulence. He had never had an issue in the past, until he increased his consumption of hummus, which contains FODMAPS. FODMAP is an acronym for fermentable, oligosaccharides, disaccharides, and polyols, which are different sugars found in a variety of foods. You can find a list of FODMAP containing foods on the internet. Avoid these foods for a week; if your symptoms resolve, then you know that gas-producing foods are to blame. You can then try to add back these foods one at a time, taking careful note of which foods cause symptoms, and which do not.
Functional dyspepsia
Functional dyspepsia refers to postprandial (after a meal) upper abdominal (above the navel) bloating, fullness, and discomfort, which is often described as a burning sensation. An upper endoscopy will not demonstrate any abnormalities. Therefore, functional dyspepsia involves bothersome symptoms without any pathology such as ulcer or tumor. Anxiety can increase symptoms. The cause is unclear, and there may be more than one cause of symptoms. One of the common series is visceral hypersensitivity, caused by abnormal processing of nerve impulses from the stomach to the brain in the presence of food. One helpful nonprescription treatment, called FDgard, is available on Amazon.com or local pharmacies, such as Rite-Aid or Wal-Mart. FDgard contains caraway oil and l-Menthol, which soothes the symptoms of functional dyspepsia – take two capsules twice daily as needed, 30-60 minutes before a meal, with water.
Irritable bowel syndrome (IBS)
Irritable bowel syndrome refers to recurring abdominal discomfort and/or bloating related to a change in bowel movements, with either decreased or increased frequency of bowel movements, or with the change in the appearance of the stool. Anxiety can increase symptoms. Like functional dyspepsia, irritable bowel syndrome is thought to be visceral hypersensitivity and abnormal gut motility. Symptoms of irritable bowel syndrome can overlap with other diagnoses in this handout. Therefore, it is important to rule out other causes such as celiac disease and SIBO, for example. A trial of eliminating gas producing foods should be undertaken. If you have chronic diarrhea, a colonoscopy with biopsies should be considered to rule out colitis, which is an inflammatory condition of the lining of the colon. There are over-the-counter and prescription treatments for constipation and diarrhea. One helpful nonprescription treatment, called IBgard, is available on Amazon.com or local pharmacies, such as Rite-Aid or Wal-Mart. IBgard contains peppermint oil, which soothes the symptoms of IBS – take one or two capsules up to 3 times daily as needed, 30-60 minutes before a meal, with water.
SIBO (small intestinal bacterial overgrowth)
The small intestine, unlike the colon, normally has few bacteria. SIBO occurs when there is an overgrowth of bacteria in the small intestine; these microbes can damage the digestive lining, decreasing digestion and absorption. SIBO tends to occur when the peristalsis (rhythmic movement of the intestine that helps to pass food and liquid through the digestive tract) is slowed;common causes include irritable bowel syndrome, diabetes (by damaging the nerves that control the movement of the intestines), and narcotic use, although there are others. Chronic use of acid suppressors such as Prilosec may have a role. SIBO can be treated with an antibiotics such as rifaximin, augmentin, and metronidazole.
Celiac disease, also called celiac sprue, or gluten enteropathy
Celiac disease is an inflammatory reaction to gluten (found within many foods) within the lining of the small intestine. This interferes with digestion and can cause symptoms. Celiac disease can be ruled out with a blood test and/or intestinal biopsy, performed by placing a fiberoptic camera through the mouth, and just past the stomach. Symptoms can resolve completely if gluten is avoided.
Constipation
Inability to completely evacuate stool (because of irritable bowel syndrome, certain medications such as narcotics, or aging, which slows the emptying of the colon) can cause a feeling of abdominal fullness, discomfort, and flatulence. Ensuring adequate fluid consumption, creasing the fiber content of your diet, and if necessary, adding a fiber supplement such as FiberCon can be helpful in treating constipation. If this is not sufficient, other treatments are available.
Pancreatic enzyme insufficiency
Digestive enzymes line the surface of the small intestine. However, the pancreas also aids in digestion by producing and releasing digestive enzymes into the small intestine. If the pancreas is unable to produce and/or release enough enzymes into the intestine for digestion, symptoms may occur. Pancreatic insufficiency can be ruled out by sending a sample of stool to measure the quantity of elastase, an enzyme produced by the pancreas. If you are found to have pancreatic insufficiency, prescription pancreas enzyme supplements are available.