Passing gas: Is it normal or a symptom of dangerous bloating?

Dr. Mimi S. Lin.



Get answers to your 20 biggest health questions on the next slide. Dr. Mimi S. Lin.



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One of my children’s favorite books is “The Gas We Pass: The Story of Farts.” My kids laugh as they learn about their bodies, but as adults we often know little about our daily bodily function and question what is normal or abnormal.

For example, how many people know a healthy individual passes gas on average 14 times per day, usually after meals? The gas we pass is a mixture of the air we swallow and our gut bacterial fermentation of the food we eat.

Bloating is caused by increased gas production or when gas is trapped in the intestines. It is experienced by up to 20 percent of healthy individuals in the United States and is a nonspecific symptom of several disorders. Excess gas production is one, but abnormal sensation of normal amounts of gas within the digestive tract, altered movements of the intestinal muscles, or abnormal abdominal wall activity are others.

Depending on other associated symptoms, the cause of bloating can be as benign as intolerance to carbohydrates to more serious disorders such as celiac disease or gastroparesis, in which the stomach muscles do not function normally.

One common and well-known form of carbohydrate maldigestion is lactose intolerance, caused when an individual does not have enough of the enzyme lactase to break lactose into absorbable form.

Excess gas might also be produced when the intestinal system is overwhelmed by too many carbohydrates. For instance, symptoms may develop after 37.5 grams of carbohydrates, the equivalent of a 12-ounce serving of either pumpkin spiced latte or apple juice, are ingested. Sorbitol, a common artificial sweetener, is also known to cause gas with as little as 5 grams, the equivalent of chewing three or four pieces of sugar-free gum.

When bloating occurs, one should always consider the possibility of a dangerous obstruction. A surgical procedure such as fundoplication to treat gastroesophageal reflux can cause gas/bloat syndrome in 73 percent of patients. Dysmotility syndromes like gastroparesis often trigger a sense of bloating or a sense of fullness. Gastroparesis is linked to a number of physiological problems like diabetes, hypothyroidism, scleroderma and medications such as opiates.

Another disease where bloating is a common is irritable bowel syndrome, which affects between 10 and 15 percent of the population. It is diagnosed by symptoms, not by a particular test.

Bloating can be managed with simple lifestyle and dietary changes or, in other cases, prescription medication. Food that causes significant gas should be avoided. These may include dairy, onions, beans, cauliflower, wheat, apples and dried fruits.

Over-the-counter medication may help with bloating. Simethicone can help rupture gas bubbles, bismuth can reduce fermentation and probiotics can modify intestinal bacteria. Antibiotics might be helpful for an overgrowth of intestinal bacteria. Those who lack enzymes may need replacement therapy.

Medications that modulate gut motor function can be useful in those with bloating caused by intestinal or gastric dysmotility. Finally, those with irritable bowel symdrome may use medication to minimize the heightened sensitivity to gas, to reduce constipation, or sometimes both. The medications can include linaclotide, lubiprostone and antidepressants.

“The Gas We Pass” may be a simple book, but bloating and gas is much more complex than it seems, a testament to the amazing complexity of our human body. Your doctor can help guide you to understand possible causes, tests and treatments.