Diagnosis of Gas or Flatulence

Gas or flatulence is a common condition for which a person visits the primary care doctor. It is diagnosed based on signs and symptoms, such as abdominal bloating, abdominal pain, passing too much gas (flatulence) and belching.

Medical history and physical examination: Your doctor will take a detailed medical history and do physical examination with special attention to your abdomen. Some of the questions that your doctor may ask include:

• What types of food do you eat usually?
• Have you made any changes in your diet recently?
• How long have you had the problem of gas?
• Do you have any other problem, such as abdominal pain, diarrhoea, early satiety (premature fullness after meals), bloating or weight loss?
• What foods have you eaten in the past few days?
• Have you recently increased fibre in your diet?
• Whether you chew and swallow slowly or fast?
• Is your gas problem mild or severe?
• Do you think that eating any specific food, such as eating milk products, increases your symptoms?
• What improves your gas and other symptoms?
• Are you taking any medication?

Your doctor may ask you to keep a food diary. This can be helpful in reviewing your dietary habits and symptoms.

Diagnostic tests: Treatment for gas is usually started based on clinical diagnosis, but if the diagnosis is not clear or some other medical condition is suspected as the cause of your symptoms, tests may be done.

• Lactase deficiency: If deficiency of lactose enzyme is suspected as the cause of gas, the doctor may take blood or breath test to diagnose lactose intolerance and suggest avoiding milk products.
• Hydrogen breathe test: The doctor may take a test to measure the amount of hydrogen in your breath after you eat suspected foods. As bacteria mostly produce hydrogen, an increase in hydrogen level in the exhaled air as measured by the breath test will suggest food intolerance. Breath test is done a few hours after eating the food that is suspected to be the cause of the problem as an increase in hydrogen level becomes evident in as little as 2 hours.

Some other tests that may be performed include:

• abdominal CT scan
• abdominal ultrasound
• barium enema x-ray
• barium swallow x-ray
• blood studies such as CBC or blood differential
• sigmoidoscopy and
• upper endoscopy (EGD).