Question

Is persistent gas (before or after meals, during the night, etc.) a sign of a more serious problem? It's got progressively worse for me lately, even though I haven't changed my diet or my lifestyle. Eating doesn't seem to affect it. I may experience severe gas pain without having eaten anything at all for a significant period of time. I'm concerned I may have a serious disease.

Answer

There are three ways that gas can be produced in the GI tract. The first is dietary, by production of gas inside the intestine (i.e. in the lumen). This can happen in several ways. The breakdown of food in the lumen by bacterial metabolism can produce hydrogen, methane and carbon dioxide. Hydrogen is produced by eating fermentable materials, such as carbohydrates and amino acids. Hydrogen is also produced in large quantities by eating certain fruits and vegetables such as baked beans.

Some people are intolerant to milk products, specifically the lactose contained in milk products. Because the large sugar molecules of disaccharide (lactose) are not absorbed they travel to the colon where they are fermented to hydrogen gas. Lactose intolerance doesn't only relate to milk, it's any form of food that has used milk in it's production including cheeses, etc.

A second major common cause of gas in the GI tract is called aerophagia. This is the simple process of swallowing air as we eat and drink. Some people with an over-production of saliva can have aerophagia caused by their constant swallowing. Loose dentures can cause aerophagia as well. Usually when someone has this problem the gas is expelled by burping rather than passing through the entire intestine.

The last cause is gas that enters the lumen from the blood stream. This is a diffusion of gas into the lumen by varying intestinal pressures. Certain antibiotics that selectively inhibit bacterial hydrogen breakdown markedly increase the amount of hydrogen excretion.

I suggest that, if you are belching and burping and your discomfort is more in your stomach, you might look for aerophagia as the cause.

Diseases that can cause excessive amounts of intestinal gas are lactase insufficiency, sprue, pancreatic insufficiency, and other causes of carbohydrate malabsorption.

Because complaints of increased gas symptoms are so nonspecific and commonly overlap other diseases and irritable bowel syndrome it's essential to see your physician for a medical exam. This is especially true if you are over 60 and believe these symptoms are new. A thorough review of your eating habits, possible causes of aerophagia, and other reasons discussed above will be made by your physician. Most cases are benign and are easily treated.