sibo breath test
What is this test used for?
The SIBO (Small Intestinal Bacterial Overgrowth) breath test is used to discover whether a patient has an overgrowth of bacteria in the small intestine, which could cause many or all of the symptoms of IBS. The theory of SIBO as a cause of IBS was developed by Dr Mark Pimentel of the Cedars-Sinai Medical Center in Los Angeles.
How is the test taken?
Patients drink a solution of lactulose syrup. For the next three hours, breath samples are taken at 15-minute intervals. Any bacteria present in the small intestine will eat the lactulose and then digest it. The digestion process produces various different types of gas, and of these, hydrogen and methane are detectable in the breath and can be measured. The levels of these gases are then used to estimate the numbers of bacteria present. The levels of gas may also correspond with the type of IBS present, as constipation sufferers tend to have higher levels of methane.
If you do not have bacteria in the small intestine, it will take around two hours before the lactulose reaches the bacteria in the colon which are present even in healthy people. Therefore, if the levels of gases rise after only a short time, and in high concentrations, it shows that bacteria are probably present in the small intestine.
What treatment can be offered based on the results of this test?
If the test is positive then the patient is treated with antibiotics - usually either Xifaxan or neomycin. They may also be given a dietary regime to follow, and possibly additional drugs such as Zelnorm.
How successful is this test in clinical studies?
A study published in the American Journal of Gastroenterology in 2003 (Pimentel M, Chow EJ, Lin HC) examined whether antibiotics could reduce IBS symptoms after an abnormal SIBO test. A total of 111 IBS patients took part in the study, and of these, 84% produced an abnormal breath test, compared with 20% in healthy controls.
Patients in the test group were treated with the antibiotic neomycin, and reported a 35% improvement in symptoms, compared to 11.4% improvement in the placebo group. Patients who had received neomycin also reported a bowel normalization of 35.3% compared to 13.9% for the placebo group. If the neomycin was successful in normalizing the results of the breath test there was a 75% improvement in symptoms.
Conclusion: Normalization of the lactulose breath test with neomycin leads to a significant reduction in IBS symptoms.
A review published in the Journal of the American Medical Association in 2004 (Lin HC) looked at previous investigations into SIBO as a cause of IBS, and bloating in particular. It was found that SIBO may explain bloating IBS because of the abnormal breath test results in 84% of IBS patients, and a 75% improvement of symptoms when the SIBO was eradicated.
Conclusion: SIBO provides a possible framework for understanding IBS, including the symptoms of bloating and distension.
Where is this test available?
The Cedars-Sinai Medical Center in Los Angeles offer the breath test to appropriate patients, and it is also available at a number of other medical centers as long as they have the required breath-measuring device. As with all IBS treatments it is best to consult your doctor about what treatment is right for you and whether this test might be helpful, and he or she can then make arrangements for the test to be carried out.
If your doctor does believe this test might be helpful and there is not a center near you which offers the breath test, a mail order test kit is also available. The kit has to be ordered by your doctor from the company QuinTron, the manufacturers of the breath testing equipment.
(Note: Dr Pimentel says in his book A New IBS Solution that patients can call Quintron directly to be told where they can find their nearest medical center which offers the breath test. However, I have been told by Quintron that this is not the case, and they are unable to give this information out to patients.)
REVIEWS OF THE SIBO BREATH TEST
Review by Susan 
I have had the breath test for SIBO three times now. I am positive every time. I have been suffering for a year. I have been on rifaximin five different times in a year. I read Dr Pimentel's book but I can't get a doctor in Atlanta to follow his protocol. I am so tired of being sick. I have suffered with this pain for three years. As soon as I take the rifaximin I am well. It just want it to last!
Review by Lisa
I have had severe IBS for about three years, but I have always had gut problems. I had several tests, went to different doctors and tried different meds. First, I changed my diet and checked out Heather Van Vorous' book for pointers. You can also get hypnosis CDs which really help with the anxiety that IBS sufferers face.
I then bought Dr Pimentel's book, A New IBS Solution. I followed the protocol in the book and my GI doctor was part of this. I had a breath test done and I was put on rifaximin (a 10-day course). I now have had two rounds of this med. The first course gave me relief for nine weeks, and this time so far I am on week 12. I'm hoping that the second round did it. I also take nortriptyline, 25mg once a day. My symptoms were mainly diarrhea and urgency. I was to the point where I thought I wouldn't be able to work or leave the house anymore.
Have you had a SIBO breath test? Please send in your review.