In this post I will discuss two things. First, we will talk about what SIBO is, what it has to do with IBS, and why it causes us so much grief. Once we have that knowledge under our belt, I will then attempt to answer a really troublesome question- why does SIBO come back again and again? The answer is actually surprisingly simple…


What is SIBO?

Small Intestinal Bacterial Overgrowth, commonly called “SIBO” (see-bow), is unique to any other kind of dysbiosis. Dysbiosis is an imbalance between the “good” and “bad” bugs that live in and on us. In the case of SIBO, it’s not a simple good/bad ratio that’s out of whack, but much of the problems arise from those bugs living in the wrong place.

The two pictures above are what I use to explain SIBO to my patients. In the picture on the left most of the bugs in our gut (shown in green) live where they belong- the colon. In the picture on the right (SIBO), however, some of those bugs have crept up where they don’t belong. The small intestine was never built to house these bugs, though. The bugs and their metabolites (fatty acids and gases) irritate the small intestine which causes inflammation, immune activation, and gas/bloating. These different gases can also influence your gut motility, which produces the symptoms of diarrhea and/or constipation.

SIBO is the most common cause of Irritable Bowel Syndrome (IBS), with different papers and experts citing an incidences ranging between 60% and 84% of all IBS cases.

Why Does SIBO Keep Coming Back?

I see a lot of people in my office whom have been treated for SIBO, only to have it come right back… sometimes multiple times! But why is this condition so notoriously hard to treat? Here are a few things I always try to untangle with my SIBO patients:

1. Did the treatment (herbal or prescription) actually kill off 100% of the overgrowth? Keep in mind that SIBO isn’t the overgrowth of just one thing, but a whole microbial community, and that different bugs are susceptible to different things. Another (different) round of critter killin’ might be in order.

2. Are you sure it’s still the SIBO? A few months ago a difficult constipation SIBO case turned out to be horribly hypothyroid. Just because you’ve had SIBO before, don’t assume those symptoms are the bugs again.

3. Were all of the contributing factors (causes) addressed? This is the one that is most frequently overlooked! If you don’t correct the environment that allowed the SIBO to grow, it WILL grow back when the antibiotics are taken away.

For example, if you take an antibiotic but you are still on your PPI omeprazole, you can bet that those bugs are going to keep coming back on you. If your SIBO is the result of autoimmunity against your intestinal neurons (subsequent to food poisoning), then you need to address that aggressively before you see full remission of your SIBO. If you are also hypothyroid (which will slow your intestinal transit time), that too will allow those bugs to creep back up into the small intestine.

Vocab Words

Bugs = Bacteria, parasites, yeasts, viruses

Dysbiosis = An imbalance in a microbial (bug) community. Places include the gut, skin, and sinuses.

PPI = Proton Pump Inhibitor (prescribed for acid reflux/GERD)


The good news is that it is possible to treat SIBO, and oftentimes that can be done naturally. No, it’s not a quick fix, but it can be done. Through a combination of dietary modifications (not low FODMAPs), exercises, and supplements, I have seen great progress be made with this notoriously hard to treat condition.

If you are ready to work with me on your IBS, please download my e-book “Why conventional Medicine CAN’T Cure IBS” below. The application process to become a patient is discussed in the last couple of pages of that book.

Best of health,

Subscribe to get my "Top 6 Causes of IBS" Guide and other Gut Health goodies.

Thanks for subscribing!