Hydrogen Breath Test on the West Bank

Diagnosing conditions with gastrointestinal symptoms

The hydrogen breath test is a test that uses the measurement of hydrogen, carbon dioxide and methane in the breath to diagnose several conditions that cause gastrointestinal symptoms.

Hydrogen breath testing is used to:

  • Assess digestion of dietary sugars, such as lactose, sucrose, fructose and sorbitol
  • Assess bacterial overgrowth of the small bowel, a condition in which larger-than-normal numbers of colonic bacteria are present in the small intestine
  • Measure whether exposure to chemicals at work affects lung function
  • Observe rapid passage of food through the small intestine.

Patients experiencing any of the conditions above may have side effects such as abdominal pain, cramps, abdominal bloating and distention, flatulence, and diarrhea.

Preparing for a hydrogen breath test

It is very important to follow the strict dietary rules before undergoing a hydrogen breath test. Certain foods can affect the test results if they are in your system at the time of testing.

Do not eat any of the following foods 24 hours prior to the test:

  • Grain products, including whole grain products, bran, or high-fiber cereals
  • Fruits, including fruit juices, apple sauce, apricots, bananas, cantaloupe, canned fruit cocktail, grapes, honeydew melon, peaches, watermelon, raw and dried fruits like raisins and berries, and yogurt that contains fruit.
  • Vegetables, including vegetable juices, potatoes, alfalfa sprouts, beets, green/yellow beans, carrots, celery, cucumber, eggplant, lettuce, mushrooms, green/red peppers, squash, zucchini, broccoli, cauliflower, Brussels sprouts, cabbage, kale, Swiss chard, beans, lentils, corn, etc.
  • Nuts, seeds, beans, including foods that may contain seeds.
  • All dairy products (except eggs), including milk, cheese, ice cream, yogurt, butter, etc.
  • Pasta
  • Steak, hamburger, pork

What you can eat before the test:

  • Baked or broiled chicken or turkey (salt and pepper only)
  • Baked or broiled fish (salt and pepper only)
  • Plain, steamed white rice
  • Eggs
  • Clear chicken or beef broth
  • White bread

You should also avoid smoking for one hour prior to the test.

The procedure

Prior to hydrogen breath testing, you will fast for at least 12 hours and will be asked about your weight. At the start of the test, you will blow into and fill a balloon with a breath of air, collecting two baseline breath samples 15 minutes apart. The concentration of hydrogen is measured in a sample of breath removed from the balloon. You will then ingest a small amount of the test sugar (lactose, sucrose, sorbitol, fructose, lactulose, etc. depending on the purpose of the test). Additional samples of breath are collected and analyzed for hydrogen every 30 minutes for three and up to five hours. Staff will also record any symptoms you experience during the test. The test is 3-hours long.


Interpretation of the results depends on the sugar that is used for testing and the pattern of hydrogen production after the sugar is ingested.

After ingestion of the dietary sugars lactose, sucrose, fructose or sorbitol, any production of hydrogen means that there has been a problem with digestion or absorption of the test sugar and that some of the sugar has reached the colon.

When rapid passage of food through the intestine is present, the test dose of lactulose reaches the colon more quickly than normally, and, therefore, hydrogen is produced by the colon’s bacteria soon after the sugar is ingested.

When bacterial overgrowth of the small bowel is present, ingestion of lactulose results in two separate periods during the test in which hydrogen is produced, an earlier period caused by the bacteria in the small intestine and a later one caused by the bacteria in the colon.

Side effects

The side effects of hydrogen breath testing are exactly what one would expect to see in individuals who poorly digest and absorb sugars and carbohydrates – patients may experience bloating, distention, pain, and diarrhea. When lactulose is used, these symptoms are unlikely to occur or are mild because the dose of lactulose used for testing is small.