top of page
  • Writer's pictureDr. Randi Brown, ND

What's Irritating Your Bowels? Is it IBS or SIBO?

Updated: Nov 25, 2023

Irritable Bowel Syndrome (IBS) is the most common gastrointestinal diagnosis with up to 20% of Canadians being affected. Functional bowel complaints, including IBS, account for 50% of all visits to gastroenterologists.

What is Irritable Bowel Syndrome?

Symptoms of IBS include abdominal pain, bloating, and altered bowel habits such as diarrhea, constipation, or alternating between the two stool consistency extremes. But IBS is just that. A constellation of symptoms with no known underlying “cause” or structural bowel changes. The symptoms of IBS are very similar to those experienced by patients with Small Intestinal Bacterial Overgrowth (SIBO). SIBO is another very common, yet frequently overlooked gut issue. SIBO symptoms typically include abdominal pain, bloating, altered bowel habits, flatulence (gas), nausea, and belching.

Could people with irritable bowel syndrome really have SIBO?

One study found that 157 of 202 (almost 80%) subjects who were considered to have IBS tested positive for SIBO.

After SIBO eradication treatment (antibiotics), about 50% of patients no longer had symptoms of IBS or SIBO.

Those who were unsuccessfully treated with antibiotics had persistent symptoms, and their breath tests did not show improvement. Therefore, there is a strong correlation with the ability to successfully treat SIBO and significantly improve or eradicate IBS symptoms.

How do I know if I have IBS or SIBO?

It is important to stress that antibiotics may only help those IBS patients who were positive for SIBO with a lactulose hydrogen breath test. Generally, IBS is not treated with antibiotics. Because many of the symptoms of SIBO and IBS overlap, the only known method to differentiate the two is through SIBO breath testing (Lactulose Breath Test). There is no test for IBS, so it is considered a diagnosis of exclusion (no other explanation for symptoms). If your SIBO breath test is positive, treatment with herbal or pharmaceutical antibiotics may be the best initial treatment option.

Can you have IBS and SIBO?

Yes. Some individuals can have both IBS and SIBO. While SIBO is a bacterial overgrowth of the small intestine, it can worsen IBS symptoms, sometimes increasing gut sensitivity to gas and pain. If treatment with antibiotics does not completely resolve your gut symptoms, additional supportive treatment for IBS may be indicated.

How do you treat SIBO?

As mentioned above, herbal or pharmaceutical antibiotics are effective in modifying bacterial overgrowth, however, further gut investigations may be necessary to rule out other food intolerances, and deficiencies. Additionally, replacing any nutrients such as B12, iron, and other micronutrients may be necessary as small bowel bacteria can reduce the absorption of these essential nutrients.

Preventing relapse: There are mechanisms in the body to help prevent naturally occurring colon bacteria from settling themselves into the small intestine, but when this system doesn't work optimally the bacteria can easily move into the small intestine. Because of this, SIBO is known to recur in many patients, therefore, treating the root cause of why you have developed SIBO in the first place is important for long-term relief of symptoms.

Big Picture

Overall both SIBO and IBS are multifactorial conditions that generally respond best to integrative and individualized treatments that may include dietary and lifestyle changes, supplements, and medications.

As a naturopathic physician, I always aim to find the root cause of your digestive issues. SIBO testing is one way I help patients navigate the complexity of the GI system, ultimately helping you increase your gut resilience so you don't have to fear foods!

If you have symptoms of IBS or SIBO, contact here to ask about SIBO breath testing and treatment options!

- Dr. Randi Brown, ND


Info on SIBO and IBS: The Canadian Society of Intestinal Research:

121 views0 comments


bottom of page