Why SIBO Keeps Coming Back (And What's Actually Driving It)
You did the protocol. Symptoms cleared, or mostly cleared. And a few months later, the bloating is back.
This is the most common story I hear about SIBO, and it isn't a sign that you did something wrong. It's a sign that the overgrowth was never the starting point.
What SIBO Actually Is
SIBO stands for small intestinal bacterial overgrowth. It happens when bacteria that belong further down in the large intestine end up in the small intestine, where they don't belong in significant numbers.
The small intestine is where you absorb most of your nutrients. When excess bacteria set up there, they compete for those nutrients and produce gas as a byproduct.
That's where the symptoms come from:
Gas and bloating, often worse as the day goes on
Burping or belching
Abdominal discomfort or pressure
Diarrhea, constipation, or alternating between them
You may have been told SIBO is the cause of your digestive trouble. That's partly true. It's causing the symptoms. But something allowed it to happen, and that's a different question.
Bacteria Overgrow When Something Upstream Isn't Working
Your small intestine has defenses against overgrowth. When bacteria take hold, it usually means one or more of those defenses has weakened.
Stomach acid. Acid is the first line of defense, sterilizing much of what you swallow before it moves on. When acid is low, more bacteria survive the trip. Acid production also tends to decline with age, which is part of why SIBO shows up more often in midlife.
Bile and pancreatic enzymes. Both have antimicrobial effects and both are essential for breaking food down. When either is sluggish, undigested food reaches the small intestine and becomes fuel for bacteria. Digestive enzymes and what they actually do is worth understanding here.
How you eat. Rushed meals, eating while stressed, not chewing thoroughly. Digestion begins before food reaches your stomach, and skipping that step affects everything downstream.
Motility. This is the one that gets missed most often, and it's usually why SIBO comes back.
The Cleanup Wave Most People Have Never Heard Of
Between meals, your small intestine runs a housekeeping process called the migrating motor complex. It's a slow wave that sweeps leftover food particles and bacteria down and out.
It only runs when you're not digesting. Every time you eat, it stops and resets.
So constant grazing, snacking between meals, or eating late into the evening means the wave rarely gets to complete. Bacteria that should have been swept along stay put.
This is also where midlife enters the picture. Progesterone has a relaxing effect on the smooth muscle of the digestive tract, and as it declines in perimenopause, motility can slow on its own. Slower motility means less effective clearing, which is one reason women who never had digestive problems start having them in their forties. Constipation in perimenopause runs on the same mechanism.
If a protocol clears an overgrowth but motility is still sluggish, the conditions that produced it are unchanged. Which is why it returns.
Why Testing for SIBO Alone Isn't the Whole Answer
Breath testing is the standard for identifying SIBO, and it's something we can run together if it's warranted, but it's not where I start with clients.
What it can't tell you is why the overgrowth happened.
That's what I'm looking at with a comprehensive stool analysis. It shows a wider view of the terrain:
Levels of beneficial bacteria
Presence of pathogens or parasites
Markers of digestive enzyme function
Inflammation and gut barrier markers
Those results don't diagnose anything. They give me the information I need to build dietary and lifestyle recommendations that address the conditions underneath, rather than working from a guess about which of the four possibilities is at play.
Confirming an overgrowth is useful. Understanding what allowed it is what changes the plan.
Addressing the Overgrowth Without Addressing the Cause
When the entire focus is on reducing bacteria, the opportunity gets missed. The bacteria weren't the origin. They were what grew in the conditions that were there.
Recurrence rates for SIBO are high, and this is why. It isn't stubbornness or bad luck. It's that the terrain didn't change.
What I work on with clients looks different:
Supporting the upstream digestive steps: stomach acid, bile flow, enzyme output
Restoring meaningful gaps between meals so the cleanup wave can actually run
Addressing nervous system state, because digestion only functions well when your body isn't braced
Using stool testing and food sensitivity testing to guide what's specific to you rather than generic
For many of my clients, this foundational work is where symptoms finally start to shift, because it changes the environment rather than just what's living in it.
Symptoms Are Signals
If you've been cycling through protocols and short-term improvements, that pattern is information.
Recurring SIBO is telling you that something upstream still needs support. Not that your body is broken, and not that you'll be managing this forever.
Your symptoms aren't unrelated. They just haven't been looked at together.
Book your complimentary consult and let's figure out what's really going on.