What Causes Excessive Gas & Bloating?

Excessive gas and bloating can be uncomfortable and socially embarrassing. Some foods, medications such as antibiotics, swallowed air, constipation and diseases can cause excessive gas. Bloating results when a buildup of gas results from lack of release through belching or flatulence, according to . Excessive gas and bloating that are accompanied by diarrhea, blood in the stool, fever, weight loss, abdominal pain and persistent heartburn should be evaluated by a physician to rule out a serious cause.

Is This an Emergency?

If you are experiencing serious medical symptoms, seek emergency treatment immediately.


Gas occurs when certain foods that are not digestible by the small intestine are instead broken down by bacteria in the large intestine, explains the National Digestive Diseases Information Clearinghouse. There may be a shortage of enzymes needed to digest some types of carbohydrates, including certain sugars, starches and fiber. Most starches, such as potatoes, corn and pasta, produce gas.

Lactose Intolerance

Lactose intolerance is a difficulty in the digestion of lactose, the sugar found in dairy products. People with lactose intolerance lack the enzyme lactase that is needed to digest lactose, according to the National Institute of Child Health and Human Development. Symptoms include excessive gas and bloating, diarrhea and abdominal pain after dairy products are consumed. Most people do not need to eliminate all dairy products from their diets, says the NICHD. Pills or drops containing lactase to aid lactose digestion are available over-the-counter, and lactose-free milk can be substituted for regular milk.

Celiac Disease

Celiac disease, also called celiac sprue, causes an intolerance to gluten, the protein found wheat, barley, rye and oats.cause:

  • Celiac disease
  • also called celiac sprue
  • causes an intolerance to gluten
  • the protein found wheat
  • barley
  • rye
  • oats

Celiac sufferers produce antibodies that damage the lining of the small intestines when they eat these grains, according to the Merck Manuals Online Medical Library. Decreased absorption of nutrients results, possibly causing anemia, nerve damage and poor bone growth. Symptoms may include

  • painful abdominal bloating
  • diarrhea
  • weight loss
  • upset stomach
  • a blistering
  • itchy skin rash

Steatorrhea, or bulky, light-colored and unusually foul-smelling stools, occurs in some patients. The treatment of celiac disease is a gluten-free diet. This can be difficult due to the wide variety of foods that contain gluten. Merck Manuals recommends expert advice from a dietitian.

Other Causes

Eating high-fat meals can also make you prone to bloating, because fat delays emptying of the stomach and can allow excess gas to build up. Stress or anxiety can also cause stomach discomfort, and gulping air when you eat or eating too quickly can cause gas and belching. Other medical conditions, such as an intestinal infection, a blockage or irritable bowel syndrome, can also raise the likelihood you'll develop a sense of gloating or experience gas.