Table of ContentsView AllTable of ContentsWho Should Be TestedSIBO Breath TestJejunal AspirationMedication Trial
Table of ContentsView All
View All
Table of Contents
Who Should Be Tested
SIBO Breath Test
Jejunal Aspiration
Medication Trial
Research suggests SIBO is underdiagnosed. You should be tested for it if you have ongoing bloating and bowel problems.Treatments for SIBOare available, so identifying it can open the door to symptom relief.
In this article, you’ll learn about each testing option, what to do before the test, and what to expect from the test itself.
Small Intestine: Function, Anatomy, and More
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Who Should Be Tested?
Experts recommend SIBO testing if you have chronic:
This is becauseirritable bowel syndrome (IBS)can be misdiagnosed in people with these symptoms.
Testing is also recommended if you have:
The diagnostic tests for SIBO are breath tests, jejunal aspiration, and a medication trial.
9 Signs Your Stomach Issues Aren’t IBS
Breath testing is non-invasive. It’s used fairly frequently as a way to look for SIBO.
When bacteria in the small intestine interact with sugar, they release hydrogen or methane. Those chemicals then come out in your breath.
For the test, you consume a sugary drink and then have your breath checked periodically. If hydrogen is detected before the 90-minute mark, it suggests SIBO.
Bacteria that produce hydrogen belong in the large intestine, not the small one. It takes about two hours for the sugar to reach the large intestine. That’s why the cutoff is 90 minutes.
The breath test is currently the primary diagnostic tool for SIBO. Although a test called the small intestine (or bowel) aspirate procedure is much more accurate, it is expensive, not yet generally available, and subject to contamination.
Despite wide use, experts are concerned about SIBO breath test validity.Unfortunately, the breath test can yield many false-positive results, especially in people who digest food faster than average.
There are two types of breath tests: One uses glucose and the other lactulose. Of the two, the glucose test seems to be better. But both are often inaccurate. The sensitivity and specificity of the tests range from 42% to 83%.
The test can also produce false negatives. That’s often because ofgastroparesis(slow emptying of the stomach).
At one time, there was no agreement about how best to perform the tests. However, in 2017, consensus was reached on what amounts of gas should be present for a positive result as well as standardization for testing, test methodology, and interpretation of results.
There is emerging research for breath tests that measure hydrogen and methane that may provide greater accuracy for diagnosis.
ProsNon-invasiveEasy to doSafeConsMany false resultsIntensive preparationTime consuming
ProsNon-invasiveEasy to doSafe
Non-invasive
Easy to do
Safe
ConsMany false resultsIntensive preparationTime consuming
Many false results
Intensive preparation
Time consuming
Before the Test
Testing should be done at a clinic or lab thattests for both hydrogenand methane. Your healthcare provider or the facility will tell you how to prepare.
During the Test
During the test, you may be asked to rinse your mouth with mouthwash. That kills any bacteria that may be present.
You’ll then give a baseline breath sample. Usually, that means blowing up a balloon. Then you’ll drink a small amount of sugary liquid.
Every 15 minutes, you’ll give them another breath sample. The test will last two to three hours, depending on the type of sugar used.
A more accurate test—but also more invasive—isjejunalaspiration.It takes place during an upperendoscopyprocedure.
An upper endoscopy involves a long tube with a camera threaded down through your mouth and throat. It’s named for the middle section of your small intestine: the jejunum.
During the endoscopy, the practitioner can take a sample. It’s then cultured and evaluated for bacteria.
Jejunal aspiration isn’t used often. It’s costly, time-consuming, and carries more risk than a breath test—although it’s generally considered safe.
Jejunal aspiration has limits to its accuracy for SIBO. False negatives are possible when:
Despite these limitations, many researchers consider jejunal aspiration the “gold standard” for SIBO testing.
Your healthcare provider or the testing center will tell you how to prepare. Those instructions will likely be similar to those for the breath test.
If you have gastroparesis, you may be told to follow a liquid diet for three days before the test.
The test will take place either at your healthcare provider’s office or at a testing facility.
Monitors may be placed on your body so your provider can keep an eye on your breathing, heart rate, and blood pressure.
An IV will most likely be started. You’ll get a mild sedative to relax you. It may not put you fully out.
Next, a numbing anesthetic will be sprayed on your throat. Then a thin tube will be inserted down your throat.
You’ll be able to breathe but not talk. Your healthcare provider will then take a sample of fluid from your small intestine using an aspiration catheter.
Then the tube will be removed from your throat. After that, you may rest for a while to allow the anesthesia to wear off.
Because you’ll be sedated, you can’t drive yourself home afterward. For the rest of the day, keep your activity to a minimum.
You may have mild side effects such as:
If you experience any severe, unusual, or worrisome symptoms (vomiting or coughing up blood), contact your healthcare provider immediately.
One way to check for SIBO is with a trial of SIBO medication. If symptoms quickly drop off, it suggests you have it.
The most common SIBO drug is Xifaxan (rifaximin)—an antibiotic.It’s different from most antibiotics, though. Rather than being absorbed into your bloodstream, it acts directly on bacteria in your small intestine.
The medical community hasn’t yet set dosing standards for SIBO trials. But some healthcare providers follow the FDA guidelines for using Xifaxan to treatdiarrhea-predominant IBS(IBS-D).
These guidelines recommend taking the medication for a two-week period, then repeating it for another one or two weeks.
This approach has limits, though.
So this approach is a tricky one to gauge.
Summary
SIBO may be underdiagnosed. If you have ongoing bowel problems, you should be tested.
Three types of SIBO testing are used:
Each approach has pros and cons for diagnosing SIBO.
8 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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Bohm M, Siwiec RM, Wo JM.Diagnosis and management of small intestinal bacterial overgrowth.Nutrition in Clinical Practice.2013;28(3):289-99. doi:10.1177/0884533613485882
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