What Are the Symptoms of SIBO?


If you’re having stomach pain, bloating, and gas, you may be suffering from small intestinal bacterial overgrowth (SIBO). Unfortunately, SIBO can be hard to diagnose on the basis of symptoms alone, since its symptoms have many similarities with those of IBS, lactose intolerance, and other gastrointestinal ailments. Here are the answers to some of the most common questions about SIBO and how you can get an accurate diagnosis. 

What causes SIBO?

SIBO is caused by specific types of bacteria colonizing the small intestine in high numbers. Normally, the small intestine harbors only very few bacteria. This overgrowth happens most often as a result of other illnesses or as a result of the treatment for such illnesses which may include acid reflux, antibiotics, surgeries, autoimmune diseases, and so on. 


While there is no established treatment plan for SIBO, a course of antibiotics can help treat or eliminate the overgrowth. The primary antibiotic used is usually Xifaxan, which has a fairly high success rate and can improve symptoms without many side effects. Other treatments include dietary changes and supplements. 


Unfortunately, unless the underlying cause is dealt with, the disorder will often return a few months after the patient has finished the course of antibiotics. If you do have SIBO, you should discuss additional testing options with your personal care provider and determine the best course of action going forward. 

How do I know if I have SIBO?

Different cases of SIBO may have slightly different symptoms, but these are some of the most common: 

  • bloating
  • gas
  • abdominal discomfort
  • cramps
  • heartburn
  • nausea
  • loose stool/diarrhea
  • constipation
  • fatigue
  • joint pain
  • rash
  • headaches
  • loss of appetite
  • sudden weight loss


The variety of possible symptoms is one of the reasons SIBO is often mistaken for IBS or another illness. In fact, some believe that undiagnosed SIBO may be the cause of over 50 percent of IBS cases. If you’ve only recently started experiencing some of these symptoms and especially if they only started after an illness appeared or a treatment or surgery was performed, you should consider testing for SIBO. 

Can I test for SIBO?

Thanks to improvements in today’s diagnostic tests, it can be relatively simple to find out if you have SIBO. There are two different types of tests that can be used for the purpose: a breath test and a culture test. 


A breath test is simple, plus you can perform it at home and then send it into a lab for verification. This type of test measures the amount of hydrogen or methane in your breath when you exhale. A breath test can help to differentiate between SIBO and IBS, and is used by gastroenterology specialists worldwide as the standard for diagnosis. It’s also non-invasive. If you go to a testing provider to perform the test rather than doing so at home, you can often get same-day results. Finally, a breath test doesn’t require the approval of your personal care physician, meaning you don’t need to obtain a referral, which can reduce the time it takes to get a diagnosis. 


The culture test is far more invasive but also can be more accurate. This test requires the oversight of a doctor, who will insert a tube down the esophagus and into the small intestine to get a sample culture. The culture then must be tested in a lab to determine whether or not you have SIBO. Considering how understaffed most health care providers are and how long it can take to get an appointment, this is hardly the most efficient option. 

Thanks to these testing options, SIBO doesn’t have to be particularly hard to diagnose. If you believe you may have SIBO, talk to your personal physician or take control of your health by getting tested today. AllClear Healthcare provides onsite SIBO testing in Boston, or you can order a test online, do the sampling for the test yourself at home, and send in the samples to our lab for expert testing. You can receive results online the same day our lab receives your test.