A hydrogen breath test provides information about the digestion of certain sugars or carbohydrates, such as milk sugar (lactose) and fruit sugar (fructose). The test is also used for detecting abnormal growth of bacteria within the small bowel. Bacterial overgrowth can cause a variety of symptoms including bloating, diarrhea, burping and abdominal cramps. The test takes ~3 hours.
Preparation for the test
For four weeks before your test, you should not take any antibiotics.
For one week before your test, avoid any laxatives and stool softeners (for example Colace®, Milk of Magnesia®, Ex-Lax®) or stool bulking agents (for example Metamucil® or Citrucel®). You should also not undergo any test that requires cleansing of the bowel, such as colonoscopy or barium enema.
The day before your test:
- You may consume only the following foods and drinks: plain white bread, plain white rice, plain white potatoes, baked or broiled chicken or fish, water, and non-flavored black coffee or tea.
- Only salt may be used to flavor your food. Butter and margarine are not permitted.
- Soda/cola drinks are not permitted.
- Do not eat or drink anything else – it could give false results for the test.
- Specifically, avoid beans, pasta, fiber cereals, and high fiber foods.
- The night before the test, have an early dinner of rice and meat.
For 12 hours before your test:
- You must stop eating and drinking 12 hours before the test. For example, if your test is at 8:00 am, you would stop eating and drinking at 8:00 pm the night before.
- You may continue to take your usual prescribed medicines with water until 12 hours before the test.
- Please bring all prescription medications to your appointment.
The day of your test:
- You should not eat or drink anything in the morning.
- You may take your medications with a small amount of water. If you are diabetic requiring insulin or diabetic pills, ask your physician if you should change your morning dose. Generally, half of your normal long-acting insulin is given. Oral hypoglycemic medications are usually not taken that morning until completion of the test and resumption of eating meals.
- Brush your teeth 2 hours before the test.
- Do not eat, drink, chew gum or tobacco, smoke cigarettes, or eat breath mints or candy before or during the test
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