What Is IMO? How It’s Different From SIBO

Understanding IMO – The Hidden Cause Behind Chronic Constipation

Have you been struggling with bloating, gas, or persistent constipation, even after trying probiotics or dietary changes? You might have heard of SIBO (Small Intestinal Bacterial Overgrowth) — but there’s another culprit that’s often overlooked: IMO, or Intestinal Methanogen Overgrowth.

At Gut Insights, we help you get clarity with our NHS-grade, CQC-regulated SIBO+IMO breath test kit, trusted by patients across the UK looking for answers to unexplained digestive issues.

What Is IMO?

IMO (Intestinal Methanogen Overgrowth) is a condition where methane-producing microbes (archaebacteria) overgrow in your gut — particularly Methanobrevibacter smithii. These methanogens are not bacteria (unlike SIBO), which is why traditional SIBO treatments sometimes don’t work for IMO sufferers.

How Is It Different from SIBO?

While both conditions involve microbial overgrowth in the small intestine, the organisms and symptoms are different.

Feature	SIBO	IMO
Microbe Type	Bacteria	Archaea
Gas Produced	Hydrogen	Methane
Common Symptom	Diarrhea	Constipation
Treatment	Rifaximin	Rifaximin + Neomycin
Diagnosis	Hydrogen on breath test	Methane ≥10ppm on breath test

In many cases, people with IMO may have normal hydrogen levels, which is why it’s critical to test for both gases – hydrogen and methane – using a reliable SIBO+IMO test kit.

How to Accurately Test for IMO and SIBO at Home

Our Gut Insights SIBO+IMO Breath Test Kit is:

NHS-grade

CQC-regulated

Simple to use from the comfort of your home

Lab-analyzed for precision (hydrogen and methane gas levels)

Unlike many kits that only test for SIBO, ours is designed to detect both SIBO and IMO using lactulose-based breath testing, providing a complete diagnostic snapshot of your small intestine health.

Why Patients Trust Gut Insights

We’re committed to clinical accuracy, patient education, and better gut health outcomes. Whether you’re working with a nutritionist, GP, or managing your gut health journey alone, Gut Insights offers the most reliable SIBO test kit and IMO test kit available in the UK.