Gas - flatulence
Gas is air in the intestine that is passed through the rectum. Air that moves from the digestive tract through the mouth is called belching.
Gas is also called flatus or flatulence.
Gas is normally formed in the intestines as your body digests food.
Gas can make you feel bloated. It can cause crampy or colicky pains in your belly.
Gas can be caused by certain foods you eat. You may have gas if you:
- Eat foods that are hard to digest, such as fiber. Sometimes, adding more fiber into your diet can cause temporary gas. Your body may adjust and stop producing gas over time.
- Eat or drink something your body cannot tolerate. For example, some people have lactose intolerance and cannot eat or drink dairy products.
Other common causes of gas are:
- Irritable bowel syndrome
- Inability to absorb nutrients properly (malabsorption)
- Inability to digest nutrients properly (maldigestion)
- Swallowing air while eating
The following tips may help you prevent gas:
- Chew your food more thoroughly.
- Do not eat beans or cabbage.
- Avoid foods high in poorly digestible carbohydrates. These are called FODMAPs and include fructose (fruit sugar).
- Avoid lactose.
- Do not drink carbonated beverages.
- Do not chew gum.
- Eat more slowly.
- Relax while you eat.
- Walk for 10 - 15 minutes after eating.
When to Contact a Medical Professional
Call your doctor or nurse if you have:
Gas and other symptoms such as stomach pain, rectal pain, heartburn, nausea, vomiting, diarrhea, constipation, fever, or weight loss
Oily, foul-smelling, or bloody stools
What to Expect at Your Office Visit
Your doctor or nurse will perform a physical exam and ask questions about your medical history and symptoms, such as:
- What foods do you commonly eat?
- Has your diet changed recently?
- Have you increased the fiber in your diet?
- How fast do you eat, chew, and swallow?
- Would you say that your gas is mild or severe?
- Does your gas seem to be related to eating milk products or other specific foods?
- What seems to make your gas better?
- What medicines do you take?
- Do you have other symptoms, like abdominal pain, diarrhea, early satiety (premature fullness after meals), bloating, or weight loss?
Tests that may be done include:
- Abdominal CT scan
- Abdominal ultrasound
- Barium enema x-ray
- Barium swallow x-ray
- Blood work such as CBC or blood differential
- Upper endoscopy (EGD)
- Breath test
PR Gibson, SJ Shepherd. Evidence-based dietary management of functional gastrointestinal symptoms: The FODMAP approach. J Gastroenterol Hepatol. 2010 Feb;25(2):252-8.
Bailey J. FPIN's Clinical Inquiries: Effective management of flatulence. Am Fam Physician. 2009;79:1098-1100.
Ohge H, Levitt MD. Intestinal gas. In: Feldman M, Friedman LS, Brandt LJ, eds. Sleisenger & Fordtran's Gastrointestinal and Liver Disease. 9th ed. Philadelphia, PA: Saunders Elsevier; 2010:chap 16.