Digestive health: the UK guide to private and integrative options

Who this guide is for

If you have been bloated, uncomfortable or unpredictable for months, your GP has tested you for coeliac disease and inflammation, everything came back normal, and you were told it is irritable bowel syndrome and to manage the stress, this is written for you.

I am a hospital doctor who also runs a private functional medicine practice in Twickenham and Richmond, and online. Digestive symptoms are one of the commonest reasons people come to me, usually after the NHS has excluded the serious things and stopped. I am going to set out what gets investigated and why, which tests are worth your money, which are not, and where private care genuinely helps and where it does not.

I have a commercial interest in you deciding to see someone privately. Read the section on what the NHS does well before you read anything else.

Before anything else: when not to read a guide

Some symptoms need assessing urgently rather than researching. If any of these apply, see your GP now and say these words, because they trigger a specific referral pathway under NICE NG12.

• Bleeding from the back passage, or blood mixed in the stool
• Unintentional weight loss you did not plan
• A change in bowel habit to looser or more frequent stools lasting six weeks or more, particularly if you are over 60
• Difficulty swallowing, or food sticking
• Persistent vomiting, or vomiting blood
• A lump you can feel in the abdomen or rectum
• Anaemia found on a blood test, especially iron deficiency without an obvious cause
• A family history of bowel or ovarian cancer alongside new symptoms

What the NHS does, and does well

It is worth being accurate about this, because a good deal of private marketing implies the NHS does nothing for gut symptoms. That is not true, and going private without completing the NHS pathway is usually a waste of money.

NICE CG61 sets out the diagnosis of irritable bowel syndrome. It is a positive diagnosis, not a dustbin: abdominal pain or discomfort that is either relieved by opening your bowels or associated with a change in how often or how formed your stools are, plus at least two of altered stool passage, bloating, symptoms made worse by eating, or passage of mucus, over at least six months.

Before that label is applied, NICE expects a full blood count, inflammatory markers, and coeliac serology. Coeliac disease is common, frequently missed, and must be tested for while you are still eating gluten - a point missed surprisingly often by people who have already cut it out.

NICE DG11 adds faecal calprotectin, which distinguishes inflammatory bowel disease from IBS in people whose symptoms could be either and in whom cancer is not suspected. It is a genuinely good test and it is available on the NHS.

NICE is also explicit about what is not needed to confirm IBS: ultrasound, sigmoidoscopy or colonoscopy, thyroid function tests, faecal ova and parasite testing, faecal occult blood, and hydrogen breath testing. If a private clinic proposes all of those as a matter of routine, ask why.

So the honest position is this. If you have not had coeliac serology and calprotectin, the most useful next step is your GP, not me.

What a private workup adds, and when

The NHS pathway is built to exclude dangerous disease and then to manage symptoms. It does the first job well. Where it stops is at the point where the tests are normal, the label is applied, and nothing further is offered.

What I add is time and breadth. A first appointment runs two hours, which is long enough to take a history that covers the things a ten-minute appointment cannot: what the symptoms actually track with, what happened in the months before they started, previous antibiotic and medication history, infections and travel, sleep, and what has been tried.

That last row matters. If you have Crohn's disease or ulcerative colitis, your specialist manages it. I can help with diet, deficiency and the things that sit around the condition, and I will write to them. I will not adjust your immunosuppression.

Tests worth paying for

Fewer than you would think from most clinic websites. These are the ones I order, and only when the history points at them.

• Coeliac serology, if it has not been done, or was done after you had already cut out gluten. Retesting requires a gluten challenge, which is unpleasant but sometimes necessary.
• Faecal calprotectin, if inflammation has not been excluded.
• Blood tests for consequences of poor absorption: iron studies, B12, folate, vitamin D, bone profile. These change management when they are abnormal, which is the test of a useful test.
• Hydrogen and methane breath testing for small intestinal bacterial overgrowth, where the history genuinely fits: bloating within an hour or two of eating, worse with fibre, often following a gut infection or abdominal surgery. I will come back to the caveats.
• Stool microscopy and culture for infection, where there has been travel or an acute onset.
• Structured elimination and reintroduction, supervised and time-limited. Not a test you buy, and more informative than most that you can.

Tests I will tell you not to buy

This is the section that will cost me money, and it is the most useful part of the page.

IgG food antibody panels

Sold widely as food sensitivity or intolerance testing, often for two to three hundred pounds, and they come back with a long list of foods to avoid. IgG antibodies to food are a normal finding and largely reflect what you have been eating. They do not identify the cause of your symptoms. The British Society for Allergy and Clinical Immunology and its European equivalent both advise against using them diagnostically.

The harm is not only the money. People eliminate fifteen or twenty foods on the strength of one, lose weight they did not need to lose, and narrow their diet in a way that makes the gut flora worse rather than better.

Direct-to-consumer microbiome reports

The science of the gut microbiome is real and genuinely interesting. The consumer tests built on it are not yet able to do what they are sold to do. A report telling you that your *Akkermansia* is low and recommending a supplement to raise it is extrapolating well past the evidence: there is no validated threshold for what a healthy individual microbiome looks like, results vary substantially between samples from the same person, and no trial shows that treating a report improves symptoms.

If you have already paid for one, bring it. I will look at it with you. I will not build a treatment plan on it.

Leaky gut and zonulin testing

Intestinal permeability is a real phenomenon and an active research area. Serum zonulin assays, as sold commercially, have been shown to cross-react with other proteins and are not a reliable measure of it. A raised or normal result would not change what I did.

Candida spit tests, hair mineral analysis, applied kinesiology, bioresonance

None of these has evidence to support it for digestive symptoms. The spit test in particular - spitting into a glass of water and interpreting what the saliva does - has no diagnostic basis at all.

What about SIBO?

Small intestinal bacterial overgrowth deserves its own answer, because it is simultaneously over-diagnosed in private practice and under-considered in general practice.

It is a real condition. Breath testing using glucose or lactulose with measurement of hydrogen and methane is the usual non-invasive approach, and the 2017 North American Consensus set out how it should be performed and interpreted. The honest position is that the test is imperfect: sensitivity and specificity are both moderate, lactulose in particular produces false positives through rapid transit, and preparation affects the result considerably.

So I use it where the history fits, and I treat the result as one piece of evidence rather than a diagnosis. I am wary of any clinic that tests everyone for it, finds it in everyone, and treats it in everyone. The recurrence rate after treatment is high, which is usually a sign that the underlying reason for it has not been addressed. The SIBO guide covers the breath test I use, what it costs and how treatment is chosen.

What treatment actually involves

Rarely a supplement protocol, which is what most people expect.

1. Getting the diagnosis right first. Including the ones that get missed: coeliac disease, bile acid diarrhoea, pancreatic insufficiency, microscopic colitis, and in women endometriosis, which is frequently mistaken for IBS for years.
2. Structured dietary work, usually time-limited. A low FODMAP approach is effective for many people with IBS, and NICE positions it as second-line advice that should be given with expert support. It is a diagnostic elimination followed by systematic reintroduction, not a diet to stay on. Staying on it long term narrows the microbiome.
3. Treating what the assessment found. That might be eradication for confirmed overgrowth, enzyme replacement for pancreatic insufficiency, correcting a deficiency, or addressing bile acid malabsorption. It might be none of those.
4. The gut-brain axis, taken seriously rather than dismissively. The nerve supply between gut and brain is bidirectional and it is not imaginary. Gut-directed hypnotherapy and cognitive behavioural therapy both have reasonable trial evidence in IBS, better than most supplements do. Being told your symptoms are stress is unhelpful; being offered a treatment that works on that pathway is not the same thing.
5. Reintroduction and widening the diet. The end point is eating more foods comfortably, not fewer.

What it costs, and the trade-offs

My fees are on the fees page in full. Across UK private practice, expect the consultation element to run from a few hundred pounds upwards depending on length and on who you are seeing, with testing separate and usually the larger cost.

The trade-offs, set out honestly:

If your symptoms are straightforward IBS and you have not yet had proper dietary support, an NHS dietitian referral is better value than me. I would rather say that now than after you have paid.

About the writer

I am Dr Andrew Greenland, GMC 4419909. I qualified in London in 1997, I am a Fellow of the Royal College of Emergency Medicine, and I still work at consultant level in an NHS hospital in west London alongside my private practice. I am a certified functional medicine practitioner.

I see patients in Twickenham and Richmond in Greater London, and online across the UK. I write to patients' GPs with their consent, and I see every patient myself.