Person clutching their abdomen, indicating stomach pain or digestive discomfort, wearing a white shirt and grey pants.

Why are the NHS still pretending SIBO doesn’t exist?

July 17, 20253 min read

By Prof Antony Hobson, Clinical Director, The Functional Gut Clinic

Millions of people across the UK are living with chronic digestive symptoms, like bloating, cramps, diarrhoea, fatigue, and being told it’s “just IBS.” But growing evidence that up to 70% of IBS patients may actually have SIBO – or Small Intestinal Bacterial Overgrowth - a condition where bacteria migrate into the small intestine, fermenting food and producing gas, pain, unpleasant tummy symptoms and malabsorption of nutrients.

This weekend I was featured in a Mail on Sunday investigation (The little-known painful digestive problem linked to fat jabs and heartburn tablets that could affect millions – but is too often missed by GPs). It is a topic I am hugely passionate about because SIBO, it’s testable, it’s treatable, and yet NHS patients are rarely offered the breath test that could confirm it. Why?

As I explained to the journalist: “The breath test may not be perfect but it’s the best tool we have currently to diagnose SIBO. Without it, patients can’t start rifaximin which means they will never get proper treatment. So refusing to test patients is as good as just giving up on them.”

SIBO is routinely overlooked, yet it’s a very easy non-invasive that can be done at home. The test can identify the type of SIBO (hydrogen, methane, or mixed), which helps tailor treatment. It predicts treatment outcomes, especially how successful rifaximin will be. But it’s not available to most NHS patients.

Some clinicians argue the breath test isn’t accurate enough. But let’s be clear: “These are patients who are in intense pain. I often hear from people who say it feels like they are being poisoned,” I told the Mail on Sunday. “Would a respiratory specialist refuse to treat a chronic chest infection with antibiotics because this might trigger side effects? No. So why is it any different with SIBO?”

Yes, rifaximin—our go-to antibiotic—is not risk-free. But neither is leaving patients untreated. SIBO can lead to IBS-type symptoms which greatly affect quality of life, nutrient deficiencies and anaemia. The trade-offs are real, but so is the suffering if doctors do nothing.

The NHS Gap

The NHS currently lacks a standardised pathway for SIBO diagnosis and treatment. GPs are not trained to spot it. Breath testing is patchy at best. And patients are left in limbo. That’s why, until the NHS catches up, The Functional Gut Clinic processes thousands of private SIBO tests every year. Our hydrogen and methane at-home breath tests are clinically validated and interpreted by expert GI physiologists to guide targeted treatment plans. We’ve helped thousands of patients who were told “it’s all in your head.” It’s not. It’s in your gut.

We urgently need:

· National NHS access to SIBO breath testing

· GP education on SIBO symptoms and risk factors

· Clear referral pathways for testing and treatment

· Recognition that IBS is not a catch-all diagnosis

Until then, we’re here to help. If you or your patients are struggling with unexplained digestive symptoms, don’t wait. Visit our SIBO page to learn more about our testing services.

To read the full article, click here.

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