3 ways to get tested for SIBO


Have you or your healthcare professional considered a diagnosis of small intestine bacterial overgrowth (SIBO) as an explanation for your chronic intestinal symptoms? New research suggests that SIBO is an undiagnosed condition that needs to be identified or ruled out for people experiencing persistent bloating and intestinal problems.

Since there are treatments for SIBO , determining its presence opens the door to symptom relief. Your healthcare professional can recommend three main options for diagnosing SIBO. Here you will learn a little about each option, what to do before the test to improve your accuracy, and what to expect from the test itself.

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Who Should Get Tested?

Out of concern that many people are being misdiagnosed with irritable bowel syndrome (IBS), researchers recommend that anyone experiencing chronic symptoms of bloating, abdominal pain, and diarrhea get tested for SIBO . SIBO should also be excluded. for anyone showing signs of nutritional deficiencies.

The SIBO test is also recommended for anyone who has worsening symptoms of the following health conditions despite proper treatment: chronic pancreatitis , Crohn 's disease, and scleroderma .

People who have celiac disease but continue to experience symptoms despite following a strict gluten-free diet can also be tested .

Breath test

The breath test is a non-invasive test that is often used as a way to diagnose or rule out SIBO. The test works by checking the breath for hydrogen or methane at regular intervals after a person drinks a liquid that contains a sugar solution such as glucose or lactulose.

The presence of hydrogen in the breath before the 90 minute mark is believed to indicate that bacteria are present in the small intestine when they interact with consumed sugar and release hydrogen or methane, which is then excreted through respiration.

This cut-off period is based on the fact that it generally takes two hours for ingested sugar to reach the intestinal bacteria that are present in the colon, where these colonies should be.

Concerns have been raised about the validity of SIBO breath tests despite their widespread use. The test gives many false positive results, especially for people who have a rapid transit time for food, as well as false negative results. more likely in people with gastroparesis (slow gastric emptying).

Also, there is no consensus on the best testing protocols and there is no consensus on the exact amount of gas in the breath that is a positive test result. However , the simplicity and security of the test are critical. the main reasons why this is the most popular way to test SIBO.


  • Non invasive

  • Easy to do

  • No danger


  • Many false positives and false negatives

  • No agreed protocol

  • There is no agreement on cutting a positive result

  • The tests require proper preparation, fasting for 12 hours and your presence for two or three hours.

Before the test

First, you need to choose a test center that tests for hydrogen and methane. Once you have done this, your healthcare provider or the test center will provide you with specific instructions on how they want you to be ready for the test.

It is important that you follow their instructions carefully to get the most accurate results. Here are some guidelines that may be recommended to you:

  • One month before : Do not use colon cleansers (such as those used before your colonoscopy ).
  • Four weeks before : Do not take antibiotics or probiotics.
  • One week before : Do not use laxatives , fiber supplements, or stool softeners .
  • Food and Drinks 48 Hours Before : Avoid carbohydrate-rich meals and snacks, especially whole grain breads or pastas. You can eat fried fish or chicken, white bread or rice, potatoes, coffee and tea.
  • Medication restriction 48 hours before taking: Talk to your healthcare provider about any medication for gastroesophageal reflux disease (GERD) to see if it should be stopped. In general, it is recommended that you stop taking any prokinetic drugs, but you can continue taking PPIs.
  • 12 hours before : Do not eat or drink anything. This includes gum and candy. If you are a smoker, don't smoke. Do not exercise, as exercise can negatively affect the test results.

During the exam

When the test begins, you may be asked to rinse your mouth with a mouthwash to clean the area of any bacteria that may be present. Then, you will be asked to take a baseline breath test, usually by blowing up a balloon. You will then be asked to drink a small amount of liquid that contains glucose or lactulose.

Every 15 minutes you will be asked to take another breath sample by blowing up a balloon. If the fluid sample contains glucose, the test can be expected to take two hours. If your liquid sample is lactulose, you can expect the test to take three hours.

Jejunal aspiration

More invasive, but more accurate in diagnosing SIBO than a breath test, is the jejunum test. This procedure is done during an upper endoscopy procedure.

To do this, you need to take a fluid sample from the middle section of the small intestine. The sample is then cultured and tested for bacteria.

Jejunal aspiration is generally not used. Its downsides are that it is expensive, time consuming, and while it is generally considered safe, it still carries a greater risk than a breath test.

Jejunal's wish also has its limitations in terms of signaling the presence of SIBO. A false negative result can occur because there is an overgrowth of bacteria in a different area than where the sample was taken (for example, further down the small intestine).

Other reasons for a false negative test result are insufficient sample size or a used culture that does not grow certain bacteria. A false positive result may be obtained if the sample has been spoiled due to bacteria in the mouth, on the instruments used, or due to poor handling of the sample.

In normal clinical practice, unlike scientific research, healthcare providers are more likely to collect a sample from the duodenum, the first part of the small intestine, than from the jejunum. Despite all these limitations, jejunal aspiration is considered by many investigators to be the "gold standard" for SIBO testing.

Before the test

Your healthcare professional or testing center will instruct you on what to do to prepare for your aspiration. These instructions are most likely similar to those for a breath test.

The only potential difference is if you have gastroparesis. In this case, you may be advised to follow a liquid diet for three days prior to the test.

During the exam

The test will be done in your healthcare provider's office or a testing center. Monitors may be placed on you to begin the procedure so your healthcare provider can monitor your breathing, heart rate, and blood pressure. You will most likely be given an IV and a light sedative that will relax you, but may not completely throw you off balance.

Then a numbing anesthetic will be given to your throat. Then a thin tube will be inserted into your throat. You won't be able to speak, but you will still be able to breathe. Next, your doctor will take a sample of fluid from your small intestine using a suction catheter.

After the procedure is complete, the tube will be removed from your throat. After that, you can rest a bit so that the effect of the anesthesia wears off. It is important to know that because the procedure requires sedation, you will not be allowed to go home after the test.

The rest of the time, you should keep your activity to a minimum. Some people experience mild side effects such as swelling, cramps, or a sore throat. If you experience any serious, unusual, or distressing symptoms (such as vomiting or coughing up blood), you should contact your healthcare professional immediately.

Drug test

A fairly common way for healthcare professionals to assess the presence of SIBO is with the SIBO drug assay. Therefore, the rapid relief of symptoms suggests that SIBO is present.

The most commonly used drug for SIBO is Xifaxan (rifaximin), which is an antibiotic. Xifaxan is different from most of the antibiotics you are familiar with because it is not absorbed by the body through the stomach. Instead, it acts locally on any bacteria that may be in the small intestine.

Although there are currently no standards for dosage and duration, healthcare providers may choose to follow the FDA guidelines for the use of xifaxan for the treatment of diarrhea-predominant IBS (IBS-D). These guidelines recommend taking the drug for two weeks and then repeating it for another week or two.

As with the other two approaches, this approach to therapeutic trials has limitations. First, as you can see, there is no recommendation on how antibiotics should be prescribed.

There are also no recommendations on what is considered a good response to a drug. All this uncertainty means that you are taking too much or too little medicine.

The future of SIBO testing

Researchers are working to better understand SIBO itself and how to improve the validity of diagnostic test methods. It is hoped that in the future, healthcare professionals will be able to identify the presence of SIBO, including indicating what types of bacteria inhabit each person's small intestine and contribute to their symptoms.

Frequently asked questions

  • Not good. There are two types of breath tests, one that uses glucose and one that uses lactulose. Of the two, the glucose test appears to be the best, but both are often inaccurate, with a sensitivity and specificity of the test ranging from 44% to 83%.

  • The symptoms of SIBO are similar to other gastrointestinal problems, including the following common signs:

    • Abdominal pain
    • Swelling (swelling)
    • Swelling
    • Diarrhea
    • Flatulence

  • You will be sedated and local anesthesia may be given to numb the areas where the scope is inserted, so you should not feel pain during the procedure. As the drug wears off, you may feel cramps and pain. If it is very painful, or if you are also coughing up blood, see your doctor.

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