How are gas problems evaluated?

Although gas is very common, at times medical evaluation is necessary. Weight loss, anemia, fevers, diarrhea, or blood in the stool should result in early evaluation.

  • The evaluation usually begins with a review of dietary habits and symptoms. Your doctor may ask you to keep a diary of foods and beverages consumed for a specific time period.
  • If lactase deficiency is the suspected cause of gas, your doctor may suggest avoiding milk products for a period of time. A blood or breath test may be used to diagnose lactose intolerance.
  • Other breath tests may be obtained to determine if there is fructose malabsorption or overgrowth of intestinal bacteria.
  • Careful review of diet and the amount of gas passed may help relate specific foods to symptoms and determine the severity of the problem.
  • If a patient complains of bloating, the doctor may examine the abdomen for the sound of fluid movement to rule out ascites (build-up of fluid in the abdomen). The doctor also may do an exam for signs of inflammation to rule out diseases of the colon.
  • The possibility of colon cancer is usually tested in people 50 years of age and older. This possibility also is tested in those with a family history of colorectal cancer, especially if they have never had a colon examination (sigmoidoscopy or colonoscopy). These tests may also be appropriate for someone with unexplained weight loss, diarrhea, or blood not visible (occult blood) in the stool.
  • For those with chronic belching, the doctor will look for signs or causes of excessive air swallowing. If needed, an upper GI series (X-ray to view the esophagus, stomach, and small intestine) may be performed to rule out disease.

How is gas treated?

Most of the time, treatment of the symptoms of gas requires an approach that includes both dietary adjustment and medication. The most common ways to reduce the discomfort of gas are changing diet, taking medication, and reducing the amount of air swallowed.

Diet

Your doctor may tell you to eat fewer foods that cause gas. However, for some people this may mean cutting out healthy foods, such as fruits and vegetables, whole grains, and milk products.Your doctor may also suggest limiting high-fat foods to reduce bloating and discomfort. This helps the stomach empty faster, allowing gases to move into the small intestine.Unfortunately, the amount of gas caused by certain foods varies from person to person. Effective dietary changes depend on learning through trial and error how much of the offending foods one can handle.

Non-prescription medicines

Many non-prescription, over-the-counter medicines are available to help reduce symptoms. Such medicines include antacids with simethicone and activated charcoal. Digestive enzymes, such as lactase supplements, actually help digest carbohydrates and may allow people to eat foods that normally cause gas. Medicines available include:

  • Antacids, such as Mylanta II®, Maalox II® and Di-Gel®, contain simethicone, a foaming agent that joins gas bubbles in the stomach so that gas is more easily belched away. The recommended dose is 2 to 4 tablespoons of the simethicone preparation taken 1/2 to 2 hours after meals.
  • Activated charcoal tablets may provide relief from gas in the colon. Studies have shown that intestinal gas is greatly reduced when these are taken before and after a meal. The usual dose is two to four tablets taken just before eating and one hour after meals.
  • For those with lactose intolerance, enzyme lactase--which aids with lactose digestion--is available in liquid and tablet form without a prescription (Lactaid®, Lactrase®, and Dairy Ease®). Adding a few drops of liquid lactase to milk before drinking it or chewing lactase tablets just before eating helps digest foods that contain lactose. Also, lactose-reduced milk and other products are available at many grocery stores.
  • Bismuth subsalicylate (Pepto-Bismol®) can reduce odor that comes from the breakdown to hydrogen sulfide. It may also be helpful for some other malodorous forms of flatus. Excess or long-term use is not suggested as it can cause bismuth toxicity in patients allergic to aspirin.
  • Beano®, an over-the-counter digestive aid, contains the sugar-digesting enzyme that the body lacks to digest the sugar in beans and many vegetables. The enzyme comes in liquid form. Three to 10 drops per serving are added to food just before eating to break down the gas-producing sugars. Beano has no effect on gas caused by lactose or fiber.
  • Probiotics are healthy bacteria that can be found in yogurt and over-the-counter supplements. It may also improve gas symptoms by changing the bacterial flora that is responsible for producing some of the gas.
  • If one experiences constipation, treatment of this disorder will be important to improve gas passage from the intestinal tract.
  • As for the discomfort of gas related to failure to advance the gas through the gastrointestinal tract, gentle exercise is important to stimulate the intestines to pass the gas through. At times, abdominal massage may also improve symptoms.

Prescription medicines

Doctors may prescribe medicines to help reduce symptoms, especially for people with a motility disorder, such as IBS. If bacterial overgrowth in the small intestines is demonstrated by testing, antibiotics to reduce these bacteria may be prescribed.

Reducing swallowed air

For those who have chronic belching, doctors may suggest ways to reduce the amount of air swallowed. Recommendations are to avoid chewing gum and to avoid eating hard candy. Eating at a slow pace and checking with a dentist to make sure dentures fit properly should also help.

Although gas may be uncomfortable and embarrassing, it is not life-threatening. Understanding the causes, ways to reduce symptoms, and treatment will help most people find some relief.

What’s important to remember about gas?

  • Everyone has gas in the digestive tract.
  • People often believe normal passage of gas to be excessive.
  • Gas comes from two main sources: swallowed air and normal breakdown of certain foods by harmless bacteria naturally present in the large intestine.
  • Many foods with carbohydrates can cause gas. Fats and proteins cause little gas.
  • Foods that may cause gas include the following:
    • Beans
    • Vegetables, such as broccoli, cabbage, brussels sprouts, onions, artichokes, and asparagus
    • Fruits, such as pears, apples, and peaches
    • Whole grains, such as whole wheat and bran
    • Soft drinks and fruit drinks
    • Milk and milk products, such as cheese and ice cream, and packaged foods prepared with lactose, such as bread, cereal, and salad dressing
    • Foods containing sorbitol, such as dietetic foods and sugar-free candies and gum
  • The most common symptoms of gas are belching, flatulence, bloating, and abdominal pain. However, some of these symptoms are often caused by an intestinal motility disorder, such as irritable bowel syndrome, rather than too much gas.
  • The most common ways to reduce the discomfort of gas are changing diet, taking nonprescription or prescription medicines, and reducing the amount of air swallowed.
  • Digestive enzymes, such as lactase supplements, actually help digest carbohydrates and may allow people to eat foods that normally cause gas in specific individuals with lactose intolerance.

Last reviewed by a Cleveland Clinic medical professional on 09/11/2020.

References

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